Up to 31,332,761 Shares of Common Stock Issuable Upon Conversion ofSeriesB Convertible Perpetual Preferred Stock Offered by Selling Stockholders The selling stockholders named in this prospectus supplement or their permitted pledgees, assignees,donees, transferees or their respective successors-in-interest (collectively, the “selling stockholders”), mayoffer and sell from time to time up to 31,332,761 shares (the “Shares”) of our common stock, par value$0.001 per share (“Common Stock”), issuable upon conversion of our SeriesB Convertible PerpetualPreferred Stock, par value $0.001 per share (the “Convertible Preferred Stock”). The 31,332,761 Shares ofCommon Stock represent the maximum number of shares of Common Stock that the Convertible PreferredStock outstanding as of July3, 2025 could be converted into through July20, 2028, assuming that alldividends are paid in-kind through such date and the application of the maximum possible conversion ratethrough such date (including the maximum possible make-whole adjustment to such conversion rate). The selling stockholders may offer, sell or distribute all or a portion of the securities hereby registeredpublicly or through private transactions at prevailing market prices or at negotiated prices. We will notreceive any of the proceeds from such sales of the Shares. We will bear all costs, expenses and fees inconnection with the registration of these securities, including with regard to compliance with state securitiesor “blue sky” laws. The selling stockholders will bear all commissions and discounts, if any, attributable totheir sale of any Shares. See the section titled “Plan of Distribution.” You should carefully read this prospectus supplement, as well as any documents incorporated byreference, before you invest in any of the securities being offered. Our Common Stock, publicly traded warrants (“Public Warrants”) and publicly tradedunits (“PublicUnits”) are listed on The Nasdaq Capital Market (“Nasdaq”) under the symbols “PCT,” “PCTTW” and“PCTTU,” respectively. On July 17, 2025, the last reported sales price of our Common Stock was $16.50per share, the last reported sales price of our Public Warrants was $5.51 per Public Warrant and the lastreported sales price of our Public Units was $21.40 per Public Unit. Our business and an investment in our Common Stock involve significant risks. These risks are describedunder the caption “Risk Factors” beginning on pageS-5of this prospectus supplement and in the documentsincorporated by reference into this prospectus supplement. Neither the Securities and Exchange Commission nor any state securities commission has approved ordisapproved of these securities or passed upon the accuracy or adequacy of this prospectus supplement. Anyrepresentation to the contrary is a criminal offense. The date of this prospectus supplement is July 18, 2025. TABLE OF CONTENTS PagePROSPECTUS SUPPLEMENTABOUT THIS PROSPECTUS SUPPLEMENTS-iiPROSPECTUS SUPPLEMENT SUMMARYS-1RISK FACTORSS-5SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTSS-7USE OF PROCEEDSS-9MATERIAL UNITED STATES FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S.HOLDERSS-10SELLING STOCKHOLDERSS-14PLAN OF DISTRIBUTIONS-23LEGAL MATTERSS-25EXPERTSS-25WHERE YOU CAN FIND ADDITIONAL INFORMATIONS-25INCORPORATION OF CERTAIN INFORMATION BY REFERENCES-26 ABOUT THIS PROSPECTUS1WHERE YOU CAN FIND MORE INFORMATION1INFORMATION WE INCORPORATE BY REFERENCE2PURECYCLE TECHNOLOGIES, INC.3CORPORATE INFORMATION4RISK FACTORS5CAUTIONARY STATEMENT ON FORWARD-LOOKING STATEMENTS6USE OF PROCEEDS8DESCRIPTION OF CAPITAL STOCK9DESCRIPTION OF WARRANTS19DESCRIPTION OF RIGHTS20DESCRIPTION OF STOCK PURCHASE CONTRACTS AND STOCK PURCHASE UNITS21DESCRIPTION OF UNITS22CERTAIN U.S. FEDERAL INCOME TAX CONSEQUENCES23FORMS OF SECURITIES24SELLING SECURITYHOLDERS26PLAN OF DISTRIBUTION27LEGAL MATTERS30EXPERTS30 ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement is part of an automatic registration statement on Form S-3ASR that wehave filed with the Securities and Exchange Commission (the “SEC”) utilizing a “shelf” registration processavailable to us as a “well-known seasoned issuer,” as defined in Rule405 under the Securities Act of 1933,as amended (the “Securities Act”). Under this shelf registration process, the selling stockholders may, fromtime to time, offer and sell, on a resale basis, the securities described in this prospectus supplement in oneor more offerings. The selling stockholders may use the shelf registration statement to sell up to anaggregate of 31,332,761 shares of Common Stock from time to time through any means described in thesection entitled “Plan of Distribution.” More specific terms of any securities that the selling stockholdersoffer and sell may be provided in a prospectus supplement that describes, among other things, the specificamounts and prices of the Shares being offered and the terms of the offering. We will not receive any proceeds from the sale by the selling stockholders of t