Exhibit 10.1

March 23, 2021

Decarbonization Plus Acquisition Corporation III

2744 Sand Hill Road

Menlo Park, CA 94025

Re: Initial Public Offering

Gentlemen:

This letter (this “Letter Agreement”) is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) to be entered into by and among Decarbonization Plus Acquisition Corporation III, a Delaware corporation (the “Company”), and Credit Suisse Securities (USA) LLC and Citigroup Global Markets Inc., as representatives (the “Representatives”) of the several underwriters (each, an “Underwriter” and collectively, the “Underwriters”), relating to an underwritten initial public offering (the “Public Offering”), of 40,250,000 of the Company’s units (including up to 5,250,000 units that may be purchased to cover over-allotments, if any) (the “Units”), each comprised of one share of the Company’s Class A common stock, par value $0.0001 per share (the “Common Stock”), and one-third of one warrant. Each whole warrant (each, a “Warrant”) entitles the holder thereof to purchase one share of Common Stock at a price of $11.50 per share, subject to adjustment. The Units shall be sold in the Public Offering pursuant to a registration statement on Form S-1 (File No. 333-253094) and prospectus (the “Prospectus”) filed by the Company with the Securities and Exchange Commission (the “Commission”) and the Company shall apply to have the Units listed on the Nasdaq Capital Market. Certain capitalized terms used herein are defined in paragraph 11 hereof.

In order to induce the Company and the Underwriters to enter into the Underwriting Agreement and to proceed with the Public Offering and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, Decarbonization Plus Acquisition Sponsor III LLC (the “Sponsor”) and each of the undersigned entities and individuals, each of whom is a member of the Company’s board of directors and/or management team, or an affiliate thereof (each, an “Insider” and collectively, the “Insiders”), hereby agrees with the Company as follows:

1.The Sponsor and each Insider agrees that if the Company seeks stockholder approval of a proposed Business Combination, then in connection with such proposed Business Combination, it, he or she shall (i) vote any shares of Capital Stock owned by it, him or her in favor of any proposed Business Combination and (ii) not redeem any shares of Common Stock owned by it, him or her in connection with such stockholder approval.

2.The Sponsor and each Insider hereby agrees that in the event that the Company fails to consummate a Business Combination within 24 months from the closing of the Public Offering, or such later period approved by the Company’s stockholders in accordance with the Company’s amended and restated certificate of incorporation, the Sponsor and each Insider shall take all reasonable steps to cause the Company to (i) cease all operations except for the purpose of winding up, (ii) as promptly as reasonably possible but not more than 10 business days

thereafter, subject to lawfully available funds therefor, redeem 100% of the Common Stock sold as part of the Units in the Public Offering (the “Offering Shares”), at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to the Company to pay its franchise and income taxes (less up to $100,000 of interest to pay dissolution expenses and net of taxes payable), divided by the number of then outstanding Offering Shares, which redemption will completely extinguish all Public Stockholders’ rights as stockholders (including the right to receive further liquidating distributions, if any), subject to applicable law, and (iii) as promptly as reasonably possible following such redemption, subject to the approval of the Company’s remaining stockholders and the Company’s board of directors, dissolve and liquidate, subject in each case to the Company’s obligations under Delaware law to provide for claims of creditors and other requirements of applicable law. The Sponsor and each Insider agrees to not propose any amendment to the Company’s amended and restated certificate of incorporation (A) that would modify the substance or timing of the Company’s obligation to redeem 100% of the Offering Shares if the Company does not complete a Business Combination within 24 months from the closing of the Public Offering or (B) or with respect to any other provision relating to the rights of holders of Common Stock or pre-initial Business Combination activity, unless the Company provides its Public Stockholders with the opportunity to redeem their Offering Shares upon approval of any such amendment at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to the Company to pay its franchise and income taxes, divided by the number of then outstanding Offering Shares.

3.During the period commencing on the effective date of the Underwriting Agreement and ending 180 days after such date, the Sponsor and each Insider shall not, without the prior written consent of the Representatives, (i) sell, offer to sell, contract or agree to sell, hypothecate, pledge, grant any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission promulgated thereunder, with respect to any Units, shares of Common Stock, Founder Shares, Warrants or any securities convertible into, or exercisable, or exchangeable for, shares of Common Stock owned by it, him or her, (ii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any Units, shares of Common Stock, Founder Shares, Warrants or any securities convertible into, or exercisable, or exchangeable for, shares of Common Stock owned by it, him or her, whether any such transaction is to be settled by delivery of such securities, in cash or otherwise, or (iii) publicly announce any intention to effect any transaction specified in clause (i) or (ii).

4.In the event of the liquidation of the Trust Account, the Sponsor (which for purposes of clarification shall not extend to any other shareholders, members or managers of the Sponsor) agrees to indemnify and hold harmless the Company against any and all loss, liability, claim, damage and expense whatsoever (including, but not limited to, any and all legal or other expenses reasonably incurred in investigating, preparing or defending against any litigation, whether pending or threatened, or any claim whatsoever) to which the Company may become subject as a result of any claim by (i) any third party (other than the Company’s independent

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accountants) for services rendered or products sold to the Company or (ii) a prospective target business with which the Company has entered into an acquisition agreement (a “Target”); provided, however, that such indemnification of the Company by the Sponsor shall apply only to the extent necessary to ensure that such claims by a third party for services rendered (other than the Company’s independent public accountants) or products sold to the Company or a Target do not reduce the amount of funds in the Trust Account to below (i) $10.00 per share of the Offering Shares or (ii) such lesser amount per share of the Offering Shares held in the Trust Account due to reductions in the value of the trust assets as of the date of the liquidation of the Trust Account, in each case, net of the amount of interest earned on the property in the Trust Account which may be withdrawn to pay taxes, except as to any claims by a third party (including a Target) who executed a waiver of any and all rights to seek access to the Trust Account and except as to any claims under the Company’s indemnity of the Underwriters against certain liabilities, including liabilities under the Securities Act of 1933, as amended. In the event that any such executed waiver is deemed to be unenforceable against such third party, the Sponsor shall not be responsible to the extent of any liability for such third party claims. The Sponsor shall have the right to defend against any such claim with counsel of its choice reasonably satisfactory to the Company if, within 15 days following written receipt of notice of the claim to the Sponsor, the Sponsor notifies the Company in writing that it shall undertake such defense.

5.To the extent that the Underwriters do not exercise their over-allotment option to purchase up to an additional 5,250,000 Units within 45 days from the date of the Prospectus (and as further described in the Prospectus), the Sponsor agrees to forfeit, at no cost, a number of Founder Shares in the aggregate equal to the product of 1,312,500 multiplied by a fraction, (i) the numerator of which is 5,250,000  minus the number of Units purchased by the Underwriters upon the exercise of their over-allotment option, and (ii) the denominator of which is 5,250,000. The forfeiture will be adjusted to the extent that the over-allotment option is not exercised in full by the Underwriters so that the Initial Stockholders will own an aggregate of 20.0% of the Company’s issued and outstanding shares of Capital Stock after the Public Offering.

6.The Sponsor and each Insider hereby agrees and acknowledges that: (i) the Underwriters and the Company would be irreparably injured in the event of a breach by such Sponsor or an Insider of its, his or her obligations under paragraphs 1, 2, 3, 4, 5, 7(a), 7(b), and 9 of this Letter Agreement, (ii) monetary damages may not be an adequate remedy for such breach and (iii) the non-breaching party shall be entitled to injunctive relief, in addition to any other remedy that such party may have in law or in equity, in the event of such breach.

7.(a) The Sponsor and each Insider agrees that it, he or she shall not Transfer any Founder Shares (or shares of Common Stock issuable upon conversion thereof) until the earlier of (A) one year after the completion of the Company’s initial Business Combination or (B) subsequent to the Business Combination, (x) if the last sale price of the Common Stock equals or exceeds $12.00 per share (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) for any 20 trading days within any 30-trading day period commencing at least 150 days after the Company’s initial Business Combination or (y) the date on which the Company completes a liquidation, merger, capital stock exchange, reorganization or other similar transaction that results in all of the Company’s stockholders having the right to

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exchange their shares of Common Stock for cash, securities or other property (the “Founder Shares Lock-up Period”).

(b) The Sponsor and each Insider agrees that it, he or she shall not Transfer any Private Placement Warrants (or shares of Common Stock issued or issuable upon the exercise of the Private Placement Warrants) until 30 days after the completion of a Business Combination (the “Private Placement Warrants Lock-up Period” and, together with the Founder Shares Lock-up Period, the “Lock-up Periods”).

(c) Notwithstanding the provisions set forth in paragraphs 7(a) and (b), Transfers of the Founder Shares, Private Placement Warrants and shares of Common Stock issued or issuable upon the exercise or conversion of the Private Placement Warrants or the Founder Shares and that are held by the Sponsor, any Insider or any of their permitted transferees (that have complied with this paragraph 7(c)), are permitted (a) to the Company’s officers or directors, any affiliates or family members of any of the Company’s officers or directors, any members of the Sponsor, or any affiliates of the Sponsor; (b) in the case of an individual, transfers by gift to a member of the individual’s immediate family, to a trust, the beneficiary of which is a member of the individual’s immediate family or an affiliate of such person, or to a charitable organization; (c) in the case of an individual, transfers by virtue of laws of descent and distribution upon death of the individual; (d) in the case of an individual, transfers pursuant to a qualified domestic relations order; (e) transfers by private sales or transfers made in connection with the consummation of a Business Combination at prices no greater than the price at which the securities were originally purchased; (f) transfers in the event of the Company’s liquidation prior to the completion of an initial Business Combination; (g) transfers by virtue of the laws of the State of Delaware or the Sponsor’s limited liability company agreement upon dissolution of the Sponsor; and (h) in the event of the Company’s liquidation, merger, capital stock exchange, reorganization or other similar transaction which results in all of the Company’s stockholders having the right to exchange their shares of Common Stock for cash, securities or other property subsequent to the completion of the Company’s initial Business Combination; provided, however, that in the case of clauses (a) through (e) and (g), these permitted transferees must enter into a written agreement agreeing to be bound by the restrictions herein.

8. The Sponsor and each Insider represents and warrants that it, he or she has never been suspended or expelled from membership in any securities or commodities exchange or association or had a securities or commodities license or registration denied, suspended or revoked. Each Insider’s biographical information furnished to the Company (including any such information included in the Prospectus) is true and accurate in all respects and does not omit any material information with respect to the Insider’s background. The Sponsor and each Insider’s questionnaire furnished to the Company is true and accurate in all respects. The Sponsor and each Insider represents and warrants that: it, he or she is not subject to or a respondent in any legal action for, any injunction, cease-and-desist order or order or stipulation to desist or refrain from any act or practice relating to the offering of securities in any jurisdiction; it, he or she has never been convicted of, or pleaded guilty to, any crime (i) involving fraud, (ii) relating to any financial transaction or handling of funds of another person, or (iii) pertaining to any dealings in any securities and it, he or she is not currently a defendant in any such criminal proceeding.

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9. Except as disclosed in the Prospectus, neither the Sponsor nor any Insider nor any affiliate of the Sponsor or any Insider, nor any director or officer of the Company, shall receive from the Company any finder’s fee, reimbursement, consulting fee, monies in respect of any repayment of a loan or other compensation prior to, or in connection with any services rendered in order to effectuate the consummation of the Company’s initial Business Combination (regardless of the type of transaction that it is), other than the following, none of which will be made from the proceeds held in the Trust Account prior to the completion of the initial Business Combination: repayment of a loan and advances up to an aggregate of $300,000 made to the Company by the Sponsor; payment to an affiliate of the Sponsor for office space, utilities and secretarial and administrative support for a total of $10,000 per month; reimbursement for any out-of-pocket expenses related to identifying, investigating, negotiating and completing an initial Business Combination; and repayment of loans, if any, and on such terms as to be determined by the Company from time to time, made by the Sponsor or any of the Company’s officers or directors to finance transaction costs in connection with an intended initial Business Combination, provided, that, if the Company does not consummate an initial Business Combination, a portion of the working capital held outside the Trust Account may be used by the Company to repay such loaned amounts so long as no proceeds from the Trust Account are used for such repayment. Up to $1,500,000 of such loans may be convertible into warrants at a price of $1.50 per warrant at the option of the lender. Such warrants would be identical to the Private Placement Warrants, including as to exercise price, exercisability and exercise period.

10. The Sponsor and each Insider has full right and power, without violating any agreement to which it is bound (including, without limitation, any non-competition or non-solicitation agreement with any employer or former employer), to enter into this Letter Agreement and, as applicable, to serve as a director on the board of directors of the Company and hereby consents to being named in the Prospectus as a director of the Company.

11. As used herein, (i) “Business Combination” shall mean a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination, involving the Company and one or more businesses; (ii) “Capital Stock” shall mean, collectively, the Common Stock and the Founder Shares; (iii) “Founder Shares” shall mean the 10,062,500 shares of the Company’s Class B common stock, par value $0.0001 per share, (or 8,750,000 shares if the over-allotment option is not exercised by the Underwriters) initially held by the Sponsor; (iv) “Initial Stockholders” shall mean the Sponsor and any other holder of Founder Shares immediately prior to the Public Offering; (v) “Private Placement Warrants” shall mean the warrants to purchase up to 6,666,667 shares of Common Stock of the Company (or 7,366,667 shares of Common Stock if the over-allotment option is exercised in full) that the Sponsor, James AC McDermott, Jeffrey Tepper, Dr. Jennifer Aaker, Jane Kearns and Michael Warren have agreed to purchase for an aggregate purchase price of $10,000,000 in the aggregate (or $11,050,000 in the aggregate if the over-allotment option is exercised in full by the Underwriters), or $1.50 per warrant, in a private placement that shall occur simultaneously with the consummation of the Public Offering; (vi) “Public Stockholders” shall mean the holders of shares of Common Stock issued in the Public Offering; (vii) “Trust Account” shall mean the trust fund into which a portion of the net proceeds of the Public Offering and the sale of the Private Placement Warrants shall be deposited; and (viii) “Transfer” shall mean the (a) sale or assignment of, offer to sell, contract or agreement to sell, hypothecate, pledge, grant of any

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option to purchase or otherwise dispose of or agreement to dispose of, directly or indirectly, or establishment or increase of a put equivalent position or liquidation with respect to or decrease of a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission promulgated thereunder with respect to, any security, (b) entry into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any security, whether any such transaction is to be settled by delivery of such securities, in cash or otherwise, or (c) public announcement of any intention to effect any transaction specified in clause (a) or (b).

12. This Letter Agreement constitutes the entire agreement and understanding of the parties hereto in respect of the subject matter hereof and supersedes all prior understandings, agreements, or representations by or among the parties hereto, written or oral, to the extent they relate in any way to the subject matter hereof or the transactions contemplated hereby. This Letter Agreement may not be changed, amended, modified or waived (other than to correct a typographical error) as to any particular provision, except by a written instrument executed by all parties hereto.

13. No party hereto may assign either this Letter Agreement or any of its rights, interests, or obligations hereunder without the prior written consent of the other parties. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall not operate to transfer or assign any interest or title to the purported assignee. This Letter Agreement shall be binding on the Sponsor and each Insider and their respective successors, heirs and assigns and permitted transferees.

14. This Letter Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York, without giving effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction. The parties hereto (i) all agree that any action, proceeding, claim or dispute arising out of, or relating in any way to, this Letter Agreement shall be brought and enforced in the courts of New York City, in the State of New York, and irrevocably submit to such jurisdiction and venue, which jurisdiction and venue shall be exclusive and (ii) waive any objection to such exclusive jurisdiction and venue or that such courts represent an inconvenient forum.

15. Any notice, consent or request to be given in connection with any of the terms or provisions of this Letter Agreement shall be in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested), by hand delivery or facsimile transmission.

16. This Letter Agreement shall terminate on the earlier of (i) the expiration of the Lock-up Periods or (ii) the liquidation of the Company; provided, however, that this Letter Agreement shall earlier terminate in the event that the Public Offering is not consummated and closed by March 31, 2022; provided further that paragraph 4 of this Letter Agreement shall survive such liquidation.

[Signature Page Follows]

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Sincerely,

DECARBONIZATION PLUS ACQUISITION SPONSOR III LLC

By: /s/Peter Haskopoulos___________________________

Name:Peter Haskopoulos

Title:Authorized Person

By: /s/Jennifer Aaker______________________________

Name:Dr. Jennifer Aaker

By: /s/Erik Anderson______________________________

Name:Erik Anderson

By: /s/Peter Haskopoulos___________________________

Name:Peter Haskopoulos

By: /s/Jane Kearns________________________________

Name:Jane Kearns

By: /s/Pierre Lapeyre______________________________

Name:Pierre Lapeyre, Jr.

By: /s/David Leuschen_____________________________

Name:David Leuschen

By: /s/James AC McDermott________________________

Name:James AC McDermott

By: /s/Jeffrey H. Tepper____________________________

Name:Jeffrey H. Tepper

By: /s/Robert Tichio_______________________________

Name:Robert Tichio

By: /s/Michael Warren_____________________________

Name:Michael Warren

[Signature Page to Letter Agreement]

Acknowledged and Agreed:

DECARBONIZATION PLUS ACQUISITION CORPORATION III

By:/s/Peter Haskopoulos___________________________________

Name: Peter Haskopoulos

Title:   Chief Financial Officer, Chief Accounting Officer and Secretary

[Signature Page to Letter Agreement]

Exhibit 10.2

INVESTMENT MANAGEMENT TRUST AGREEMENT

This Investment Management Trust Agreement (this “Agreement”) is made effective as of March 23, 2021 by and between Decarbonization Plus Acquisition Corporation III, a Delaware corporation (the “Company”), and Continental Stock Transfer & Trust Company, a New York corporation (the “Trustee”).

WHEREAS, the Company’s registration statement on Form S-1, No. 333-253094 (the “Registration Statement”) and prospectus (the “Prospectus”) for the initial public offering of the Company’s units (the “Units”), each of which consists of one share of the Company’s Class A common stock, par value $0.0001 per share (the “Common Stock”), and one-third of one warrant, each whole warrant entitling the holder thereof to purchase one share of Common Stock (such initial public offering hereinafter referred to as the “Offering”), has been declared effective as of the date hereof by the U.S. Securities and Exchange Commission; and

WHEREAS, the Company has entered into an Underwriting Agreement (the “Underwriting Agreement”) with Credit Suisse Securities (USA) LLC and Citigroup Global Markets Inc. as representatives (the “Representatives”) of the several underwriters (the “Underwriters”) named therein; and

WHEREAS, as described in the Prospectus, $350,000,000 of the gross proceeds of the Offering and sale of the Private Placement Warrants (as defined in the Underwriting Agreement) (or $402,500,000 if the Underwriters’ over-allotment option is exercised in full) will be delivered to the Trustee to be deposited and held in a segregated trust account located at all times in the United States (the “Trust Account”) for the benefit of the Company and the holders of the Common Stock included in the Units issued in the Offering as hereinafter provided (the amount to be delivered to the Trustee (and any interest subsequently earned thereon) is referred to herein as the “Property,” the stockholders for whose benefit the Trustee shall hold the Property will be referred to as the “Public Stockholders,” and the Public Stockholders and the Company will be referred to together as the “Beneficiaries”); and

WHEREAS, pursuant to the Underwriting Agreement, a portion of the Property equal to $12,250,000, or $14,087,500 if the Underwriters’ over-allotment option is exercised in full, is attributable to deferred underwriting discounts and commissions that may be payable by the Company to the Underwriters upon the consummation of the Business Combination (as defined below) (the “Deferred Discount”); and

WHEREAS, the Company and the Trustee desire to enter into this Agreement to set forth the terms and conditions pursuant to which the Trustee shall hold the Property.

NOW THEREFORE, IT IS AGREED:

1. Agreements and Covenants of Trustee. The Trustee hereby agrees and covenants to:

(a) Hold the Property in trust for the Beneficiaries in accordance with the terms of this Agreement in the Trust Account established by the Trustee at J.P. Morgan Chase Bank, N.A. (or

at another U.S. chartered commercial bank with consolidated assets of $100 billion or more) in the United States, maintained by the Trustee and at a brokerage institution selected by the Trustee that is reasonably satisfactory to the Company;

(b) Manage, supervise and administer the Trust Account subject to the terms and conditions set forth herein;

(c) In a timely manner, upon the written instruction of the Company, invest and reinvest the Property in United States government securities within the meaning of Section 2(a)(16) of the Investment Company Act of 1940, as amended, having a maturity of 185 days or less, or in money market funds meeting the conditions of paragraphs (d)(1), (d)(2), (d)(3) and (d)(4) of Rule 2a-7 promulgated under the Investment Company Act of 1940, as amended (or any successor rule), which invest only in direct U.S. government treasury obligations, as determined by the Company; the Trustee may not invest in any other securities or assets, it being understood that the Trust Account will earn no interest while account funds are uninvested awaiting the Company’s instructions hereunder and the trustee may earn bank credits or other considerations;

(d) Collect and receive, when due, all interest or other income arising from the Property, which shall become part of the “Property,” as such term is used herein;

(e) Promptly notify the Company of all communications received by the Trustee with respect to any Property requiring action by the Company;

(f) Supply any necessary information or documents as may be requested by the Company (or its authorized agents) in connection with the Company’s preparation of the tax returns relating to assets held in the Trust Account;

(g) Participate in any plan or proceeding for protecting or enforcing any right or interest arising from the Property if, as and when instructed by the Company to do so;

(h) Render to the Company monthly written statements of the activities of, and amounts in, the Trust Account reflecting all receipts and disbursements of the Trust Account;

(i) Commence liquidation of the Trust Account only after and promptly after (x) receipt of, and only in accordance with, the terms of a letter from the Company (“Termination Letter”) in a form substantially similar to that attached hereto as either Exhibit A or Exhibit B, as applicable, signed on behalf of the Company by its Chief Executive Officer, President, Chief Financial Officer, Secretary or Chairman of the board of directors of the Company (the “Board”) or other authorized officer of the Company, and complete the liquidation of the Trust Account and distribute the Property in the Trust Account, including interest not previously released to the Company to pay its franchise and income taxes (less up to $100,000 of interest that may be released to the Company to pay dissolution expenses and net of taxes payable), only as directed in the Termination Letter and the other documents referred to therein, or (y) upon the date which is the later of (i) 24 months after the closing of the Offering and (ii) such later date as may be approved by the Company’s stockholders in accordance with the Company’s amended and restated certificate of incorporation, if a Termination Letter has not been received by the Trustee

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prior to such date, in which case the Trust Account shall be liquidated in accordance with the procedures set forth in the Termination Letter attached as Exhibit B and the Property in the Trust Account, including interest not previously released to the Company to pay its franchise and income taxes (less up to $100,000 of interest that may be released to the Company to pay dissolution expenses and net of taxes payable) shall be distributed to the Public Stockholders of record as of such date;

(j) Upon written request from the Company, which may be given from time to time in a form substantially similar to that attached hereto as Exhibit C (a “Tax Payment Withdrawal Instruction”), withdraw from the Trust Account and distribute to the Company the amount of interest earned on the Property requested by the Company to cover any income or franchise tax obligation owed by the Company as a result of assets of the Company or interest or other income earned on the Property, which amount shall be delivered directly to the Company by electronic funds transfer or other method of prompt payment, and the Company shall forward such payment to the relevant taxing authority; provided, however, that to the extent there is not sufficient cash in the Trust Account to pay such tax obligation, the Trustee shall liquidate such assets held in the Trust Account as shall be designated by the Company in writing to make such distribution; provided, further, that if the tax to be paid is a franchise tax, the written request by the Company to make such distribution shall be accompanied by a copy of the franchise tax bill from the State of Delaware for the Company and a written statement from the principal financial officer of the Company setting forth the actual amount payable. The written request of the Company referenced above shall constitute presumptive evidence that the Company is entitled to said funds, and the Trustee shall have no responsibility to look beyond said request;

(k) Upon written request from the Company, which may be given from time to time in a form substantially similar to that attached hereto as Exhibit D (a “Stockholder Redemption Withdrawal Instruction”), the Trustee shall distribute on behalf of the Company the amount requested by the Company to be used to redeem shares of Common Stock from Public Stockholders properly submitted in connection with a stockholder vote to approve an amendment to the Company’s amended and restated certificate of incorporation (A) to modify the substance or timing of the Company’s obligation to redeem 100% of its public shares of Common Stock if the Company has not consummated an initial Business Combination within such time as is described in the Company’s amended and restated certificate of incorporation or (B) with respect to any other provision relating to the rights of holders of Common Stock or pre-initial Business Combination activity. The written request of the Company referenced above shall constitute presumptive evidence that the Company is entitled to distribute said funds, and the Trustee shall have no responsibility to look beyond said request; and

(l) Not make any withdrawals or distributions from the Trust Account other than pursuant to Section 1(i), (j) or (k) above.

2. Agreements and Covenants of the Company. The Company hereby agrees and covenants to:

(a) Give all instructions to the Trustee hereunder in writing, signed by the Company’s Chairman of the Board, President, Chief Executive Officer, Chief Financial Officer or Secretary.

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In addition, except with respect to its duties under Sections 1(i), 1(j) and 1(k) hereof, the Trustee shall be entitled to rely on, and shall be protected in relying on, any verbal or telephonic advice or instruction which it, in good faith and with reasonable care, believes to be given by any one of the persons authorized above to give written instructions, provided that the Company shall promptly confirm such instructions in writing;

(b) Subject to Section 4 hereof, hold the Trustee harmless and indemnify the Trustee from and against any and all expenses, including reasonable counsel fees and disbursements, or losses suffered by the Trustee in connection with any action taken by it hereunder and in connection with any action, suit or other proceeding brought against the Trustee involving any claim, or in connection with any claim or demand, which in any way arises out of or relates to this Agreement, the services of the Trustee hereunder, or the Property or any interest earned on the Property, except for expenses and losses resulting from the Trustee’s gross negligence, fraud or willful misconduct. Promptly after the receipt by the Trustee of notice of demand or claim or the commencement of any action, suit or proceeding, pursuant to which the Trustee intends to seek indemnification under this Section 2(b), it shall notify the Company in writing of such claim (hereinafter referred to as the “Indemnified Claim”). The Trustee shall have the right to conduct and manage the defense against such Indemnified Claim; provided that the Trustee shall obtain the consent of the Company with respect to the selection of counsel, which consent shall not be unreasonably withheld. The Trustee may not agree to settle any Indemnified Claim without the prior written consent of the Company, which such consent shall not be unreasonably withheld. The Company may participate in such action with its own counsel;

(c) Pay the Trustee the fees set forth on Schedule A hereto, including an initial acceptance fee, annual administration fee, and transaction processing fee which fees shall be subject to modification by the parties from time to time. It is expressly understood that the Property shall not be used to pay such fees unless and until it is distributed to the Company pursuant to Sections 1(i) through 1(k) hereof. The Company shall pay the Trustee the initial acceptance fee and the first annual administration fee at the consummation of the Offering. The Company shall not be responsible for any other fees or charges of the Trustee except as set forth in this Section 2(c), Schedule A and as may be provided in Section 2(b) hereof;

(d) In connection with any vote of the Company’s stockholders regarding a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination involving the Company and one or more businesses (the “Business Combination”), provide to the Trustee an affidavit or certificate of the inspector of elections for the stockholder meeting verifying the vote of such stockholders regarding such Business Combination;

(e) Provide the Representatives with a copy of any Termination Letter(s) and/or any other correspondence that is sent to the Trustee with respect to any proposed withdrawal from the Trust Account promptly after it issues the same;

(f) Instruct the Trustee to make only those distributions that are permitted under this Agreement, and refrain from instructing the Trustee to make any distributions that are not permitted under this Agreement; and

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(g) Within four (4) business days after the Underwriters exercise the over-allotment option (or any unexercised portion thereof) or such over-allotment option expires, provide the Trustee with a notice in writing of the total amount of the Deferred Discount, which shall in no event be less than $12,250,000.

3. Limitations of Liability. The Trustee shall have no responsibility or liability to:

(a) Imply obligations, perform duties, inquire or otherwise be subject to the provisions of any agreement or document other than this Agreement and that which is expressly set forth herein;

(b) Take any action with respect to the Property, other than as directed in Section 1 hereof, and the Trustee shall have no liability to any party except for liability arising out of the Trustee’s gross negligence, fraud or willful misconduct;

(c) Institute any proceeding for the collection of any principal and income arising from, or institute, appear in or defend any proceeding of any kind with respect to, any of the Property unless and until it shall have received instructions from the Company given as provided herein to do so and the Company shall have advanced or guaranteed to it funds sufficient to pay any expenses incident thereto;

(d) Refund any depreciation in principal of any Property;

(e) Assume that the authority of any person designated by the Company to give instructions hereunder shall not be continuing unless provided otherwise in such designation, or unless the Company shall have delivered a written revocation of such authority to the Trustee;

(f) The other parties hereto or to anyone else for any action taken or omitted by it, or any action suffered by it to be taken or omitted, in good faith and in the Trustee’s best judgment, except for the Trustee’s gross negligence, fraud or willful misconduct. The Trustee may rely conclusively and shall be protected in acting upon any order, notice, demand, certificate, opinion or advice of counsel (including counsel chosen by the Trustee, which counsel may be the Company’s counsel), statement, instrument, report or other paper or document (not only as to its due execution and the validity and effectiveness of its provisions, but also as to the truth and acceptability of any information therein contained) which the Trustee believes, in good faith and with reasonable care, to be genuine and to be signed or presented by the proper person or persons. The Trustee shall not be bound by any notice or demand, or any waiver, modification, termination or rescission of this Agreement or any of the terms hereof, unless evidenced by a written instrument delivered to the Trustee, signed by the proper party or parties and, if the duties or rights of the Trustee are affected, unless it shall give its prior written consent thereto;

(g) Verify the accuracy of the information contained in the Registration Statement;

(h) Provide any assurance that any Business Combination entered into by the Company or any other action taken by the Company is as contemplated by the Registration Statement;

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(i) File information returns with respect to the Trust Account with any local, state or federal taxing authority or provide periodic written statements to the Company documenting the taxes payable by the Company, if any, relating to any interest income earned on the Property;

(j) Prepare, execute and file tax reports, income or other tax returns and pay any taxes with respect to any income generated by, and activities relating to, the Trust Account, regardless of whether such tax is payable by the Trust Account or the Company, including, but not limited to, franchise and income tax obligations, except pursuant to Section 1(j) hereof; or

(k) Verify calculations, qualify or otherwise approve the Company’s written requests for distributions pursuant to Sections 1(i), 1(j) and 1(k) hereof.

4. Trust Account Waiver. The Trustee has no right of set-off or any right, title, interest or claim of any kind (“Claim”) to, or to any monies in, the Trust Account, and hereby irrevocably waives any Claim to, or to any monies in, the Trust Account that it may have now or in the future. In the event the Trustee has any Claim against the Company under this Agreement, including, without limitation, under Section 2(b) or Section 2(c) hereof, the Trustee shall pursue such Claim solely against the Company and its assets outside the Trust Account and not against the Property or any monies in the Trust Account.

5. Termination. This Agreement shall terminate as follows:

(a) If the Trustee gives written notice to the Company that it desires to resign under this Agreement, the Company shall use its reasonable efforts to locate a successor trustee, pending which the Trustee shall continue to act in accordance with this Agreement. At such time that the Company notifies the Trustee that a successor trustee has been appointed and has agreed to become subject to the terms of this Agreement, the Trustee shall transfer the management of the Trust Account to the successor trustee, including but not limited to the transfer of copies of the reports and statements relating to the Trust Account, whereupon this Agreement shall terminate; provided, however, that in the event that the Company does not locate a successor trustee within ninety (90) days of receipt of the resignation notice from the Trustee, the Trustee may submit an application to have the Property deposited with any court in the State of New York or with the United States District Court for the Southern District of New York and upon such deposit, the Trustee shall be immune from any liability whatsoever; or

(b) At such time that the Trustee has completed the liquidation of the Trust Account and its obligations in accordance with the provisions of Section 1(i) hereof (which section may not be amended under any circumstances) and distributed the Property in accordance with the provisions of the Termination Letter, this Agreement shall terminate except with respect to Section 2(b).

6. Miscellaneous.

(a) The Company and the Trustee each acknowledge that the Trustee will follow the security procedures set forth below with respect to funds transferred from the Trust Account. The Company and the Trustee will each restrict access to confidential information relating to such

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security procedures to authorized persons. Each party must notify the other party immediately if it has reason to believe unauthorized persons may have obtained access to such confidential information, or of any change in its authorized personnel. In executing funds transfers, the Trustee shall rely upon all information supplied to it by the Company, including account names, account numbers, and all other identifying information relating to a Beneficiary, Beneficiary’s bank or intermediary bank. Except for any liability arising out of the Trustee’s gross negligence, fraud or willful misconduct, the Trustee shall not be liable for any loss, liability or expense resulting from any error in the information or transmission of the funds.

(b) This Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York, without giving effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction. This Agreement may be executed in several original or facsimile counterparts, each one of which shall constitute an original, and together shall constitute but one instrument.

(c) This Agreement contains the entire agreement and understanding of the parties hereto with respect to the subject matter hereof. This Agreement or any provision hereof may only be changed, amended or modified (other than to correct a typographical error) by a writing signed by each of the parties hereto.

(d) This Agreement or any provision hereof may only be changed, amended or modified pursuant to Section 6(c) hereof with the Consent of the Stockholders, it being the specific intention of the parties hereto that each of the Company’s stockholders is, and shall be, a third party beneficiary of this Section 6(d) with the same right and power to enforce this Section 6(d) as the other parties hereto. For purposes of this Section 6(d), the “Consent of the Stockholders” means receipt by the Trustee of a certificate from the inspector of elections of the stockholder meeting certifying that either (i) the Company’s stockholders of record as of a record date established in accordance with Section 213(a) of the Delaware General Corporation Law, as amended (“DGCL”) (or any successor rule), who hold sixty-five percent (65%) or more of all then outstanding shares of the Common Stock and Class B common stock, par value $0.0001 per share, of the Company voting together as a single class, have voted in favor of such change, amendment or modification, or (ii) the Company’s stockholders of record as of the record date who hold sixty-five percent (65%) or more of all then outstanding shares of the Common Stock and Class B common stock, par value $0.0001 per share, of the Company voting together as a single class, have delivered to such entity a signed writing approving such change, amendment or modification. Except for any liability arising out of the Trustee’s gross negligence, fraud or willful misconduct, the Trustee may rely conclusively on the certification from the inspector of elections referenced above and shall be relieved of all liability to any party for executing the proposed amendment in reliance thereon.

(e) The parties hereto consent to the jurisdiction and venue of any state or federal court located in the City of New York, State of New York, for purposes of resolving any disputes hereunder. AS TO ANY CLAIM, CROSS-CLAIM OR COUNTERCLAIM IN ANY WAY RELATING TO THIS AGREEMENT, EACH PARTY WAIVES THE RIGHT TO TRIAL BY JURY.

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(f) Any notice, consent or request to be given in connection with any of the terms or provisions of this Agreement shall be in writing and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested), by hand delivery or by facsimile or email transmission:

if to the Trustee, to:

Continental Stock Transfer & Trust Company

1 State Street, 30^th Floor

New York, New York 10004

Attn: Francis Wolf and Celeste Gonzalez

Email: fwolf@continentalstock.com

Email: cgonzalez@continentalstock.com

if to the Company, to:

Decarbonization Plus Acquisition Corporation III

2744 Sand Hill Road

Menlo Park, CA 94025

Attn: Peter Haskopoulos

Email: phaskopoulos@riverstonellc.com

in each case, with copies to:

Vinson & Elkins L.L.P.

1001 Fannin Street, Suite 2500

Houston, Texas 77002

Attn: Ramey Layne

Email: rlayne@velaw.com

and

Credit Suisse Securities (USA) LLC

Eleven Madison Avenue

New York, New York 10010-3629

Attn: Niron Stabinsky

and

Citigroup Global Markets Inc.

388 Greenwich Street

New York, New York 10013

Attn: Pavan Bellur

Email: pavan.bellur@citi.com

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(g) Each of the Company and the Trustee hereby represents that it has the full right and power and has been duly authorized to enter into this Agreement and to perform its respective obligations as contemplated hereunder. The Trustee acknowledges and agrees that it shall not make any claims or proceed against the Trust Account, including by way of set-off, and shall not be entitled to any funds in the Trust Account under any circumstance.

(h) Each of the Company and the Trustee hereby acknowledges and agrees that each of the Representatives, on behalf of the Underwriters, is a third party beneficiary of this Agreement.

(i) Except as specified herein, no party to this Agreement may assign its rights or delegate its obligations hereunder to any other person or entity.

[Signature Page Follows]

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IN WITNESS WHEREOF, the parties have duly executed this Investment Management Trust Agreement as of the date first written above.

Continental Stock Transfer & Trust Company, as Trustee

By:_/s/Francis Wolf______________________________

Name:Francis Wolf

Title:Vice President

Decarbonization Plus Acquisition Corporation III

By: _/s/Peter Haskopoulos_________________________

Name:Peter Haskopoulos

[Signature Page to Investment Management Trust Agreement]

Exhibit 10.3

REGISTRATION RIGHTS AGREEMENT

THIS REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of March 23, 2021, is made and entered into by and among Decarbonization Plus Acquisition Corporation III, a Delaware corporation (the “Company”), Decarbonization Plus Acquisition Sponsor III LLC, a Delaware limited liability company (the “Sponsor”), and the undersigned parties listed under Holder on the signature page hereto (each such party, together with the Sponsor and any person or entity who hereafter becomes a party to this Agreement pursuant to Section 5.2 of this Agreement, a “Holder” and collectively the “Holders”).

RECITALS

WHEREAS, the Sponsor, Dr. Jennifer Aaker, Jane Kearns, Jim McDermott, Jeffrey H. Tepper and Michael Warren own an aggregate of 10,062,500 shares of the Company’s Class B common stock, par value $0.0001 per share (the “Founder Shares”);

WHEREAS, the Founder Shares will automatically convert into shares of the Company’s Class A common stock, par value $0.0001 per share (the “Common Stock”), at the time of the Company’s initial Business Combination (as defined below) on a one-for-one basis, subject to adjustment, on the terms and conditions provided in the Company’s amended and restated certificate of incorporation;

WHEREAS, on March 23, 2021, the Company, the Sponsor, Dr. Jennifer Aaker, Jane Kearns, Jim McDermott, Jeffrey H. Tepper and Michael Warren (collectively, the “Purchasers”) entered into that certain Private Placement Warrants Purchase Agreement, pursuant to which the Sponsor and the Purchasers agreed to purchase an aggregate of 6,666,667 warrants (or 7,366,667 warrants if the over-allotment option in connection with the Company’s initial public offering is exercised in full) (the “Private Placement Warrants”) in a private placement transaction occurring simultaneously with the closing of the Company’s initial public offering; and

WHEREAS, the Company and the Holders desire to enter into this Agreement, pursuant to which the Company shall grant the Holders certain registration rights with respect to certain securities of the Company, as set forth in this Agreement.

NOW, THEREFORE, in consideration of the representations, covenants and agreements contained herein, and certain other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto, intending to be legally bound, hereby agree as follows:

ARTICLE I
DEFINITIONS

“Agreement” shall have the meaning given in the Preamble.

“Board” shall mean the Board of Directors of the Company.

“Business Combination” shall mean any merger, capital stock exchange, asset acquisition, stock purchase, reorganization or other similar business combination with one or more businesses, involving the Company.

“Commission” shall mean the Securities and Exchange Commission.

“Common Stock” shall have the meaning given in the Recitals hereto.

“Company” shall have the meaning given in the Preamble.

“Demand Registration” shall have the meaning given in subsection 2.1.1 of this Agreement.

“Demanding Holder” shall mean, (i) for purposes of a Demand Registration, any Holder or group of Holders, that together holds Registrable Securities having an aggregate value of at least $25 million, at the time of the written demand, and (ii) for purposes of an Underwritten Demand, any Holder or group of Holders, that together elects to dispose of Registrable Securities having an aggregate value of at least $25 million, at the time of the Underwritten Demand, under a Registration Statement pursuant to an Underwritten Offering.

“Effectiveness Period” shall have the meaning given in subsection 3.1.1 of this Agreement.

“Exchange Act” shall mean the Securities Exchange Act of 1934, as it may be amended from time to time.

“Form S-3” shall mean Form S-3 or any similar short-form registration statement that may be available at such time.

“Founder Shares” shall have the meaning given in the Recitals hereto.

“Holder Indemnified Persons” shall have the meaning given in subsection 4.1.1 of this Agreement.

“Holders” shall have the meaning given in the Preamble.

“Maximum Number of Securities” shall have the meaning given in subsection 2.1.4 of this Agreement.

“Misstatement” shall mean an untrue statement of a material fact or an omission to state a material fact required to be stated in a Registration Statement or necessary to make the statements therein not misleading, or an untrue statement of a material fact or an omission to state a material fact necessary to make the statements in a Prospectus, in the light of the circumstances under which they were made, not misleading.

“Piggyback Registration” shall have the meaning given in subsection 2.2.1 of this Agreement.

“Private Placement Warrants” shall have the meaning given in the Recitals hereto.

“Pro Rata” shall have the meaning given in subsection 2.1.4 of this Agreement.

“Prospectus” shall mean the prospectus included in any Registration Statement, as supplemented by any and all prospectus supplements and as amended by any and all post-effective amendments and including all material incorporated by reference in such prospectus.

“Registrable Security” shall mean (a) the shares of Common Stock issued or issuable upon the conversion of any Founder Shares, (b) the Private Placement Warrants (including any shares of Common Stock issued or issuable upon the exercise of any such Private Placement Warrants), (c) any equity securities (including the shares of Common Stock issued or issuable upon the exercise of any such equity security) of the Company issuable upon conversion of any working capital loans in an amount up to $1,500,000 made to the Company by a Holder, (d) any outstanding share of Common Stock or any other equity security (including the shares of Common Stock issued or issuable upon the exercise of any other equity security) of the Company held by a Holder as of the date of this Agreement and (e) any other equity security of the Company issued or issuable with respect to any such share of Common Stock by way of a stock dividend or stock split or in connection with a combination of shares, recapitalization, merger, consolidation or reorganization; provided, however, that, as to any particular Registrable Security, such securities shall cease to be Registrable Securities when: (A) a Registration Statement with respect to the sale of such securities shall have become effective under the Securities Act and such securities shall have been sold, transferred, disposed of or exchanged in accordance with such Registration Statement; (B) such securities shall have been otherwise transferred, new certificates for such securities not bearing a legend restricting further transfer shall have been delivered by the Company and subsequent public distribution of such securities shall not require registration under the Securities Act; (C) such securities shall have ceased to be outstanding; or (D) such securities may be sold without registration pursuant to Rule 144 promulgated under the Securities Act (or any successor rule promulgated thereafter by the Commission) (but with no volume or other restrictions or limitations).

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“Registration” shall mean a registration effected by preparing and filing a registration statement or similar document in compliance with the requirements of the Securities Act, and the applicable rules and regulations promulgated thereunder, and any such registration statement having been declared effective by, or become effective pursuant to rules promulgated by, the Commission.

“Registration Expenses” shall mean the out-of-pocket expenses of a Registration, including, without limitation, the following:

“Registration Statement” shall mean any registration statement under the Securities Act that covers the Registrable Securities pursuant to the provisions of this Agreement, including the Prospectus included in such registration statement, amendments (including post-effective amendments) and supplements to such registration statement, and all exhibits to and all material incorporated by reference in such registration statement.

“Requesting Holder” shall have the meaning given in subsection 2.1.3 of this Agreement.

“Securities Act” shall mean the Securities Act of 1933, as amended from time to time.

“Sponsor” shall have the meaning given in the Preamble.

“Suspension Event” shall have the meaning given in Section 3.4 of this Agreement.

“Underwriter” shall mean a securities dealer who purchases any Registrable Securities as principal in an Underwritten Offering and not as part of such dealer’s market-making activities.

“Underwritten Demand” shall have the meaning given in subsection 2.1.3 of this Agreement.

“Underwritten Offering” shall mean a Registration in which securities of the Company are sold to an Underwriter in a firm commitment underwriting for distribution to the public.

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4

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(a)If the Registration or Underwritten Offering is undertaken for the Company’s account, the Company shall include in any such Registration or Underwritten Offering (A) first, the Common Stock or other equity securities of the Company that the Company desires to sell, which can be sold without exceeding the Maximum Number of Securities; (B) second, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (A), the Registrable Securities of Holders exercising their rights to register their Registrable Securities pursuant to subsection 2.2.1 of this Agreement, Pro Rata, which can be sold without exceeding the Maximum Number of Securities; and (C) third, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A) and (B), Common Stock or other equity securities of the Company, if any, as to which Registration or Underwritten Offering has been requested pursuant to written contractual piggyback registration rights of other stockholders of the Company, which can be sold without exceeding the Maximum Number of Securities; or

(b)If the Registration or Underwritten Offering is pursuant to a request by persons or entities other than the Holders of Registrable Securities, then the Company shall include in any such Registration or Underwritten Offering (A) first, Common Stock or other equity securities of the Company, if any, of such requesting persons or entities, other than the Holders of Registrable Securities, which can be sold without exceeding the Maximum Number of Securities; (B) second, to the extent that the Maximum Number of Securities has not been reached under the foregoing clause (A), the Registrable Securities of Holders exercising their rights to register their Registrable Securities pursuant to subsection 2.2.1 of this Agreement, Pro Rata, which can be sold without exceeding the Maximum Number of Securities; (C) third, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A) and (B), Common Stock or other equity securities of the Company that the Company desires to sell, which can be sold without exceeding the Maximum Number of Securities; and (D) fourth, to the extent that the Maximum Number of Securities has not been reached under the foregoing clauses (A), (B) and (C), Common Stock or other equity securities of the Company for the account of other persons or entities that the Company is obligated to register pursuant to separate written contractual arrangements with such persons or entities, which can be sold without exceeding the Maximum Number of Securities.

2.3Restrictions on Registration Rights. If (A) the Holders have requested an Underwritten Offering pursuant to an Underwritten Demand and the Company and the Holders are unable to obtain the commitment of underwriters to firmly underwrite the offer; or (B) the Holders have requested a Demand Registration or an Underwritten Offering pursuant to an Underwritten Demand and in the good faith judgment of the Board such Registration or Underwritten Offering would be seriously detrimental to the Company and the Board concludes as a result that it is essential to defer the filing of such Registration Statement or the undertaking of such Underwritten Offering at such time, then in each case the Company shall furnish to such Holders a certificate signed by the Chairman of the Board stating that in the good faith judgment of the Board it would be seriously detrimental to the Company for such Registration Statement to be filed or to undertake such Underwritten Offering in the near future and that it is therefore essential to defer the filing of such Registration Statement or undertaking of such Underwritten Offering. In such event, the Company shall have the right to defer such filing or offering for a period

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of not more than thirty (30) days; provided, however, that the Company shall not defer its obligation in this manner more than once in any twelve (12)-month period.

ARTICLE III
COMPANY PROCEDURES

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3.4Suspension of Sales. Notwithstanding anything to the contrary in this Agreement, the Company shall be entitled to (A) delay or postpone the (i) initial effectiveness of any Registration Statement or (ii) launch of any Underwritten Offering, in each case, filed or requested pursuant to this Agreement, and (B) from time to time to require the Holders not to sell under any Registration Statement or Prospectus or to suspend the effectiveness thereof, if the negotiation or consummation of a transaction by the Company or its subsidiaries is pending or an event has occurred, which negotiation, consummation or event, the Board reasonably believes, upon the advice of legal counsel, would require additional disclosure by the Company in the applicable Registration Statement or Prospectus of material information that the Company has a bona fide business purpose for keeping confidential and the non-disclosure of which in the Registration Statement or Prospectus would be expected, in the reasonable determination of the Board, upon the advice of legal counsel, to cause the Registration Statement or Prospectus to fail to comply with applicable disclosure requirements (each such circumstance, a “Suspension Event”); provided, however, that the Company may not delay or suspend a Registration Statement, Prospectus or Underwritten Offering on more than two occasions, for more than sixty (60) consecutive calendar days, or more than ninety (90) total calendar days, in each case during any twelve-month period. Upon receipt of any written notice from the Company of a Suspension Event while a Registration Statement filed pursuant to this Agreement is effective or if as a result of a Suspension Event a Misstatement exists, each Holder agrees that (i) it will immediately discontinue offers and sales of Registered Securities under each Registration Statement filed pursuant to this Agreement until the Holder receives copies of a supplemental or amended Prospectus (which the Company agrees to promptly prepare) that corrects the relevant misstatements or omissions and receives notice that any post-effective amendment has become effective or unless otherwise notified by the Company that it may resume such offers and sales and (ii) it will maintain the confidentiality of information included in such written notice delivered by the Company unless otherwise required by law or subpoena. If so directed by the Company, the Holders will deliver to the Company or, in Holders’ sole discretion destroy, all copies of each Prospectus covering Registrable Securities in Holders’ possession; provided, however, that this obligation to deliver or destroy shall not apply (A) to the extent the Holders are required to retain a copy of such Prospectus (x) to comply with applicable legal, regulatory, self-regulatory or professional requirements or (y) in accordance with a bona fide pre-existing document retention policy or (B) to copies stored electronically on archival servers as a result of automatic data back-up.

3.5Reporting Obligations. As long as any Holder shall own Registrable Securities, the Company, at all times while it shall be a reporting company under the Exchange Act, covenants to file timely (or obtain extensions in respect thereof and file within the applicable grace period) all reports required to be filed by the Company after the date hereof pursuant to Section 13(a) or 15(d) of the Exchange Act. The Company further covenants that it shall take such further action as any Holder may reasonably request, all to the extent required from time to time to enable such Holder to sell shares of Registrable Securities held by such Holder without registration under the Securities Act within the limitation of the exemptions provided by Rule 144 promulgated under the Securities Act (or any successor rule promulgated thereafter by the Commission), including providing any legal opinions. Upon the request of any Holder, the Company shall deliver to such Holder a written certification of a duly authorized officer as to whether it has complied with such requirements.

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ARTICLE V
MISCELLANEOUS

5.2.1This Agreement and the rights, duties and obligations of the Company hereunder may not be assigned or delegated by the Company in whole or in part.

5.2.2This Agreement and the provisions hereof shall be binding upon and shall inure to the benefit of each of the parties and its successors.

5.2.3This Agreement shall not confer any rights or benefits on any persons that are not parties hereto, other than as expressly set forth in this Agreement and Section 5.2 of this Agreement.

5.2.4No assignment by any party hereto of such party’s rights, duties and obligations hereunder shall be binding upon or obligate the Company unless and until the Company shall have received (i) written notice of such assignment as provided in Section 5.1 of this Agreement and (ii) the written agreement of the assignee, in a form reasonably satisfactory to the Company, to be bound by the terms and provisions of this

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Agreement (which may be accomplished by an addendum or certificate of joinder to this Agreement). Any transfer or assignment made other than as provided in this Section 5.2 shall be null and void.

[SIGNATURE PAGES FOLLOW]

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IN WITNESS WHEREOF, the undersigned have caused this Agreement to be executed as of the date first written above.

COMPANY:

DECARBONIZATION PLUS ACQUISITION CORPORATION III,

a Delaware corporation

By: /s/Peter Haskopoulos

Name: Peter Haskopoulos

Title: Chief Financial Officer, Chief Accounting   Officer and Secretary

HOLDERS:

DECARBONIZATION PLUS ACQUISITION SPONSOR III LLC,

a Delaware limited liability company

By: /s/Peter Haskopoulos

Name: Peter Haskopoulos

Title: Officer

/s/James AC McDermott

James AC McDermott

/s/Jeffrey H. Tepper

Jeffrey H. Tepper

/s/Jennifer Aaker

Dr. Jennifer Aaker

/s/Jane Kearns

Jane Kearns

/s/Michael Warren

Michael Warren

[Signature Page to Registration Rights Agreement]

Exhibit 10.4

DECARBONIZATION PLUS ACQUISITION CORPORATION III

2744 Sand Hill Road

Menlo Park, CA 94025

March 23, 2021

Riverstone Equity Partners LP

712 Fifth Avenue, 36^th Floor

New York, NY 10019

Re: Administrative Support Agreement

Gentlemen:

This letter agreement by and between Decarbonization Plus Acquisition Corporation III (the “Company”) and Riverstone Equity Partners LP (“Riverstone”), an affiliate of our sponsor, Decarbonization Plus Acquisition Sponsor III LLC, dated as of the date hereof, will confirm our agreement that, commencing on the date the securities of the Company are first listed on the NASDAQ Capital Market (the “Listing Date”), pursuant to a Registration Statement on Form S-1 and prospectus filed with the Securities and Exchange Commission (the “Registration Statement”) and continuing until the earlier of the consummation by the Company of an initial business combination or the Company’s liquidation (in each case as described in the Registration Statement) (such earlier date hereinafter referred to as the “Termination Date”):

(i) Riverstone shall make available to the Company, at 712 Fifth Avenue, 36^th Floor, New York, NY 10019 (or any successor location of Riverstone), certain office space, utilities and secretarial and administrative support as may be reasonably required by the Company. In exchange therefor, the Company shall pay Riverstone the sum of $10,000 per month on the Listing Date and continuing monthly thereafter until the Termination Date; and

(ii) Riverstone hereby irrevocably waives any and all right, title, interest, causes of action and claims of any kind as a result of, or arising out of, this letter agreement (each, a “Claim”) in or to, and any and all right to seek payment of any amounts due to it out of, the trust account established for the benefit of the public stockholders of the Company and into which substantially all of the proceeds of the Company’s initial public offering will be deposited (the “Trust Account”), and hereby irrevocably waives any Claim it may have in the future, which Claim would reduce, encumber or otherwise adversely affect the Trust Account or any monies or other assets in the Trust Account, and further agrees not to seek recourse, reimbursement, payment or satisfaction of any Claim against the Trust Account or any monies or other assets in the Trust Account for any reason whatsoever.

This letter agreement constitutes the entire agreement and understanding of the parties hereto in respect of its subject matter and supersedes all prior understandings, agreements, or representations by or among the parties hereto, written or oral, to the extent they relate in any way to the subject matter hereof or the transactions contemplated hereby.

This letter agreement may not be amended, modified or waived as to any particular provision, except by a written instrument executed by the parties hereto.

No party hereto may assign either this letter agreement or any of its rights, interests, or obligations hereunder without the prior written approval of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall not operate to transfer or assign any interest or title to the purported assignee.

This letter agreement constitutes the entire relationship of the parties hereto, and any litigation between the parties (whether grounded in contract, tort, statute, law or equity) shall be governed by, construed in accordance with, and interpreted pursuant to the laws of the State of New York, without giving effect to its choice of laws principles.

[Signature Page Follows]

Very truly yours,

DECARBONIZATION PLUS ACQUISITION CORPORATION III

By:/s/Peter Haskopoulos

Name:Peter Haskopoulos

[Signature Page to Administrative Support Agreement]

AGREED TO AND ACCEPTED BY:

RIVERSTONE EQUITY PARTNERS LP

By: RIVERSTONE HOLDINGS LLC,

its general partner

By: /s/Peter Haskopoulos

Name: Peter Haskopoulos

Title:   Authorized Officer

[Signature Page to Administrative Support Agreement]

Exhibit 10.5

PRIVATE PLACEMENT WARRANTS PURCHASE AGREEMENT

THIS PRIVATE PLACEMENT WARRANTS PURCHASE AGREEMENT, effective as of March 23, 2021 (as it may from time to time be amended, this “Agreement”), is entered into by and among Decarbonization Plus Acquisition Corporation III, a Delaware corporation (the “Company”), and each of the parties set forth on the signature page hereto under “Purchasers” (the “Purchasers”).

WHEREAS:

The Company intends to consummate an initial public offering of the Company’s units (the “Public Offering”), each unit consisting of one share of the Company’s Class A common stock, par value $0.0001 per share (each, a “Share”), and one-third of one warrant as set forth in the Company’s registration statement on Form S-1, filed with the Securities and Exchange Commission (the “SEC”), File Number 333-253094 (the “Registration Statement”), under the Securities Act of 1933, as amended (the “Securities Act”);

Each whole warrant entitles the holder to purchase one Share at an exercise price of $11.50 per Share; and

The Purchasers have agreed to purchase an aggregate of 6,666,667 warrants (or up to 7,366,667 warrants if the over-allotment option in connection with the Public Offering is exercised in full) (the “Private Placement Warrants”), each Private Placement Warrant entitling the holder to purchase one Share at an exercise price of $11.50 per Share.

NOW THEREFORE, in consideration of the mutual promises contained in this Agreement and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties to this Agreement hereby, intending legally to be bound, agree as follows:

AGREEMENT

Section 1.Authorization, Purchase and Sale; Terms of the Private Placement

Warrants.

A.Authorization of the Private Placement Warrants. The Company has duly authorized the issuance and sale of the Private Placement Warrants to the Purchasers.

B.Purchase and Sale of the Private Placement Warrants. On the date that is one business day prior to the date of the consummation of the Public Offering or on such earlier time and date as may be mutually agreed by the Purchasers and the Company (the “Initial Closing Date”), the Company shall issue and sell to the Purchasers, and the Purchasers shall purchase from the Company the Private Placement Warrants set forth opposite such Purchaser’s name on Exhibit A to this Agreement at a price of $1.50 per warrant for an aggregate purchase price of approximately $10,000,000 (the “Purchase Price”), which shall be paid by wire transfer of immediately available funds to the Company in accordance with the Company’s wiring instructions. On the Initial Closing Date, upon the payment by the Purchasers of the Purchase Price set forth opposite such Purchaser’s name on Exhibit A to this Agreement by wire transfer of immediately available funds to the Company, the Company shall, at its option, deliver a certificate evidencing the Private Placement Warrants purchased on such date duly registered in such Purchaser’s name to each Purchaser, or effect such delivery in book-entry form. On the date that is one business day prior to each date of the consummation of the closing of the over-allotment option in connection with the Public Offering or on such earlier time and date as may be mutually agreed by Decarbonization Plus Acquisition Sponsor III LLC, a Delaware limited liability company (the “Sponsor”), and the Company (each such date, an “Over-allotment Closing Date,” and each Over-allotment Closing Date (if any) and the Initial Closing Date being sometimes referred to herein as a “Closing Date”), the Company shall issue and sell to the Sponsor, and the Sponsor shall purchase from the Company, up to an aggregate of 700,000 Private Placement Warrants at a price of $1.50 per warrant for an aggregate purchase price of up to $1,050,000 (if the over-allotment option in connection with the Public Offering is exercised in full) (the “Over-allotment Purchase Price”), which shall be paid by wire transfer of immediately available funds to the Company in accordance with the Company’s wiring

instructions. On the Over-allotment Closing Date, upon the payment by the Sponsor of the Over-allotment Purchase Price by wire transfer of immediately available funds to the Company, the Company shall, at its option, deliver a certificate evidencing the Private Placement Warrants purchased on such date duly registered in the Sponsor’s name to the Sponsor, or effect such delivery in book-entry form.

C.Terms of the Private Placement Warrants.

(i)Each Private Placement Warrant shall have the terms set forth in a Warrant Agreement to be entered into by the Company and a warrant agent, in connection with the Public Offering (the “Warrant Agreement”).

(ii)At the time of the closing of the Public Offering, the Company and the Purchasers shall enter into a registration rights agreement (the “Registration Rights Agreement”) pursuant to which the Company will grant certain registration rights to the Purchasers relating to the Private Placement Warrants and the Shares underlying the Private Placement Warrants.

Section 2.Representations and Warranties of the Company. As a material inducement to the Purchasers to enter into this Agreement and purchase the Private Placement Warrants, the Company hereby represents and warrants to the Purchasers (which representations and warranties shall survive each Closing Date) that:

A.Organization and Corporate Power. The Company is a corporation duly organized, validly existing and in good standing under the laws of the State of Delaware and is qualified to do business in every jurisdiction in which the failure to so qualify would reasonably be expected to have a material adverse effect on the financial condition, operating results or assets of the Company. The Company possesses all requisite corporate power and authority necessary to carry out the transactions contemplated by this Agreement and the Warrant Agreement.

B.Authorization; No Breach.

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(i)The execution, delivery and performance of this Agreement and the Private Placement Warrants have been duly authorized by the Company as of the Closing Date. This Agreement constitutes the valid and binding obligation of the Company, enforceable in accordance with its terms. Upon issuance in accordance with, and payment pursuant to, the terms of the Warrant Agreement and this Agreement, the Private Placement Warrants will constitute valid and binding obligations of the Company, enforceable in accordance with their terms as of the Closing Date.

(ii)The execution and delivery by the Company of this Agreement and the Private Placement Warrants, the issuance and sale of the Private Placement Warrants, the issuance of the Shares upon exercise of the Private Placement Warrants and the fulfillment of and compliance with the respective terms hereof and thereof by the Company, do not and will not as of the Closing Date (a) conflict with or result in a breach of the terms, conditions or provisions of, (b) constitute a default under, (c) result in the creation of any lien, security interest, charge or encumbrance upon the Company’s capital stock or assets under, (d) result in a violation of, or (e) require any authorization, consent, approval, exemption or other action by or notice or declaration to, or filing with, any court or administrative or governmental body or agency pursuant to the Certificate of Incorporation of the Company or the Amended and Restated Bylaws of the Company (in effect on the date hereof or as may be amended prior to completion of the contemplated Public Offering), or any material law, statute, rule or regulation to which the Company is subject, or any agreement, order, judgment or decree to which the Company is subject, except for any filings required after the date hereof under federal or state securities laws.

C.Title to Securities. Upon issuance in accordance with, and payment pursuant to, the terms hereof and the Warrant Agreement, the Shares issuable upon exercise of the Private Placement Warrants will be duly and validly issued, fully paid and nonassessable. Upon issuance in accordance with, and payment pursuant to, the terms hereof and the Warrant Agreement, each Purchaser will have good title to the Private Placement Warrants purchased by such Purchaser and the Shares issuable upon exercise of such Private Placement Warrants, free and clear of all liens, claims and encumbrances of any kind, other than (i) transfer restrictions hereunder and under the other agreements contemplated hereby, (ii) transfer restrictions under federal and state securities laws, and (iii) liens, claims or encumbrances imposed due to the actions of such Purchaser.

D.Governmental Consents. No permit, consent, approval or authorization of, or declaration to or filing with, any governmental authority is required in connection with the execution, delivery and performance by the Company of this Agreement or the consummation by the Company of any other transactions contemplated hereby.

Section 3. Representations and Warranties of the Purchasers. As a material inducement to the Company to enter into this Agreement and issue and sell the Private Placement Warrants to the Purchasers, each Purchaser hereby, severally and not jointly, represents and warrants to the Company (which representations and warranties shall survive each Closing Date) that:

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A.Organization and Requisite Authority. Such Purchaser possesses all requisite power and authority necessary to carry out the transactions contemplated by this Agreement.

B.Authorization; No Breach.

(i)This Agreement constitutes a valid and binding obligation of such Purchaser, enforceable in accordance with its terms, subject to bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and other laws of general applicability relating to or affecting creditors’ rights and to general equitable principles (whether considered in a proceeding in equity or law).

(ii)The execution and delivery by such Purchaser of this Agreement and the fulfillment of and compliance with the terms hereof by such Purchaser does not and shall not as of each Closing Date conflict with or result in a breach by such Purchaser of the terms, conditions or provisions of any agreement, instrument, order, judgment or decree to which such Purchaser is subject.

C.Investment Representations.

(i)Such Purchaser is acquiring the Private Placement Warrants and, upon exercise of the Private Placement Warrants, the Shares issuable upon such exercise (collectively, the “Securities”) for such Purchaser’s own account, for investment purposes only and not with a view towards, or for resale in connection with, any public sale or distribution thereof.

(ii)Such Purchaser is an “accredited investor” as such term is defined in Rule 501(a)(3) of Regulation D under the Securities Act.

(iii)Such Purchaser understands that the Securities are being offered and will be sold to it in reliance on specific exemptions from the registration requirements of the United States federal and state securities laws and that the Company is relying upon the truth and accuracy of, and such Purchaser’s compliance with, the representations and warranties of such Purchaser set forth herein in order to determine the availability of such exemptions and the eligibility of such Purchaser to acquire such Securities.

(iv)Such Purchaser did not decide to enter into this Agreement as a result of any general solicitation or general advertising within the meaning of Rule 502(c) of Regulation D under the Securities Act.

(v)Such Purchaser has been furnished with all materials relating to the business, finances and operations of the Company and materials relating to the offer and sale of the Securities which have been requested by such Purchaser. Such Purchaser has been afforded the opportunity to ask questions of the executive officers and directors of the Company. Such Purchaser understands that its investment in the Securities involves a high degree of risk and such Purchaser has sought such accounting, legal and tax advice as such Purchaser has considered necessary to make an informed investment decision with respect to the acquisition of the Securities.

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(vi)Such Purchaser understands that no United States federal or state agency or any other government or governmental agency has passed on or made any recommendation or endorsement of the Securities or the fairness or suitability of the investment in the Securities by such Purchaser nor have such authorities passed upon or endorsed the merits of the offering of the Securities.

(vii)Such Purchaser understands that: (a) the Securities have not been and are not being registered under the Securities Act or any state securities laws, and may not be offered for sale, sold, assigned or transferred unless (1) subsequently registered thereunder or (2) sold in reliance on an exemption therefrom; (b) except as specifically set forth in the Registration Rights Agreement, neither the Company nor any other person is under any obligation to register the Securities under the Securities Act or any state securities laws or to comply with the terms and conditions of any exemption thereunder; and (c) Rule 144 adopted pursuant to the Securities Act will not be available for resale transactions of Securities prior to a Business Combination and may not be available for resale transactions of Securities after a Business Combination.

(viii)Such Purchaser has such knowledge and experience in financial and business matters, knows of the high degree of risk associated with investments in the securities of companies in the development stage such as the Company, is capable of evaluating the merits and risks of an investment in the Securities and is able to bear the economic risk of an investment in the Securities in the amount contemplated hereunder for an indefinite period of time. Such Purchaser has adequate means of providing for such Purchaser’s current financial needs and contingencies and will have no current or anticipated future needs for liquidity which would be jeopardized by the investment in the Securities. Such Purchaser can afford a complete loss of such Purchaser’s investment in the Securities.

Section 4.Conditions of the Purchasers’ Obligations. The obligations of the Purchasers to purchase and pay for the Private Placement Warrants are subject to the fulfillment, on or before each Closing Date, of each of the following conditions:

A.Representations and Warranties. The representations and warranties of the Company contained in Section 2 shall be true and correct at and as of such Closing Date as though then made.

B.Performance. The Company shall have performed and complied with all agreements, obligations and conditions contained in this Agreement that are required to be performed or complied with by it on or before such Closing Date.

C.No Injunction. No litigation, statute, rule, regulation, executive order, decree, ruling or injunction shall have been enacted, entered, promulgated or endorsed by or in any court or governmental authority of competent jurisdiction or any self-regulatory organization having authority over the matters contemplated hereby, which prohibits the consummation of any of the transactions contemplated by this Agreement or the Warrant Agreement.

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D.Warrant Agreement. The Company shall have entered into a Warrant Agreement with a warrant agent on terms satisfactory to the Purchasers.

Section 5.Conditions of the Company’s Obligations. The obligations of the Company to the Purchasers under this Agreement are subject to the fulfillment, on or before each Closing Date, of each of the following conditions:

A.Representations and Warranties. The representations and warranties of the Purchasers contained in Section 3 shall be true and correct at and as of such Closing Date as though then made.

B.Performance. The Purchasers shall have performed and complied with all agreements, obligations and conditions contained in this Agreement that are required to be performed or complied with by the Purchasers on or before such Closing Date.

C.Corporate Consents. The Company shall have obtained the consent of its Board of Directors authorizing the execution, delivery and performance of this Agreement and the Warrant Agreement and the issuance and sale of the Private Placement Warrants hereunder.

D.No Injunction. No litigation, statute, rule, regulation, executive order, decree, ruling or injunction shall have been enacted, entered, promulgated or endorsed by or in any court or governmental authority of competent jurisdiction or any self-regulatory organization having authority over the matters contemplated hereby, which prohibits the consummation of any of the transactions contemplated by this Agreement or the Warrant Agreement.

E.Warrant Agreement. The Company shall have entered into a Warrant Agreement with a warrant agent on terms satisfactory to the Company.

Section 6.Termination. This Agreement may be terminated at any time after December 31, 2021 upon the election by either the Company or the Sponsor upon written notice to the other parties if the closing of the Public Offering does not occur prior to such date.

Section 7.Survival of Representations and Warranties. All of the representations and warranties contained herein shall survive each Closing Date.

Section 8.Definitions. Terms used but not otherwise defined in this Agreement shall have the meaning assigned to such terms in the Registration Statement.

Section 9.Miscellaneous.

A.Successors and Assigns. Except as otherwise expressly provided herein, all covenants and agreements contained in this Agreement by or on behalf of any of the parties hereto shall bind and inure to the benefit of the respective successors of the parties hereto whether so expressed or not. Notwithstanding the foregoing or anything to the contrary herein, the parties may not assign this Agreement, other than assignments by the Purchasers to affiliates thereof (including, without limitation, one or more of the Sponsor’s members).

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B.Severability. Whenever possible, each provision of this Agreement shall be interpreted in such manner as to be effective and valid under applicable law, but if any provision of this Agreement is held to be prohibited by or invalid under applicable law, such provision shall be ineffective only to the extent of such prohibition or invalidity, without invalidating the remainder of this Agreement.

C.Counterparts. This Agreement may be executed simultaneously in two or more counterparts, none of which need contain the signatures of more than one party, but all such counterparts taken together shall constitute one and the same agreement.

D.Descriptive Headings; Interpretation. The descriptive headings of this Agreement are inserted for convenience only and do not constitute a substantive part of this Agreement. The use of the word “including” in this Agreement shall be by way of example rather than by limitation.

E.Governing Law. This Agreement shall be deemed to be a contract made under the laws of the State of New York and for all purposes shall be construed in accordance with the internal laws of the State of New York.

F.Amendments. This Agreement may not be amended, modified or waived as to any particular provision, except by a written instrument executed by all parties hereto.

[Signature page follows]

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IN WITNESS WHEREOF, the parties hereto have executed this Agreement to be effective as of the date first set forth above.

COMPANY:

DECARBONIZATION PLUS ACQUISITION CORPORATION III

By:/s/Peter Haskopoulos_______________________________________

Name:Peter Haskopoulos

Title:Chief Financial Officer, Chief Accounting Officer and Secretary

PURCHASERS:

DECARBONIZATION PLUS ACQUISITION SPONSOR III LLC

By:/s/Peter Haskopoulos_____________________________________

Name:Peter Haskopoulos

Title:Chief Financial Officer, Chief Accounting Officer and Secretary

/s/Jennifer Aaker______________________________________________

Dr. Jennifer Aaker

/s/Jane Kearns________________________________________________

Jane Kearns

/s/James AC McDermott________________________________________

James AC McDermott

/s/Jeffrey Tepper______________________________________________

Jeffrey Tepper

/s/Michael Warren_____________________________________________

Michael Warren

[Signature Page to Private Placement Warrants Purchase Agreement]

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