<SEC-DOCUMENT>0001708035-24-000106.txt : 20240806
<SEC-HEADER>0001708035-24-000106.hdr.sgml : 20240806
<ACCEPTANCE-DATETIME>20240806160110
ACCESSION NUMBER:		0001708035-24-000106
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20240805
FILED AS OF DATE:		20240806
DATE AS OF CHANGE:		20240806

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Feehan Michael
		CENTRAL INDEX KEY:			0001874994
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38221
		FILM NUMBER:		241178959

	MAIL ADDRESS:	
		STREET 1:		C/O PQ GROUP HOLDINGS INC.
		STREET 2:		300 LINDENWOOD DRIVE
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Ecovyst Inc.
		CENTRAL INDEX KEY:			0001708035
		STANDARD INDUSTRIAL CLASSIFICATION:	CHEMICALS & ALLIED PRODUCTS [2800]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		IRS NUMBER:				813406833
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		300 LINDENWOOD DRIVE
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355
		BUSINESS PHONE:		484-617-1200

	MAIL ADDRESS:	
		STREET 1:		300 LINDENWOOD DRIVE
		CITY:			MALVERN
		STATE:			PA
		ZIP:			19355

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PQ Group Holdings Inc.
		DATE OF NAME CHANGE:	20170531
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1722974463.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-08-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001708035</issuerCik>
        <issuerName>Ecovyst Inc.</issuerName>
        <issuerTradingSymbol>ECVT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001874994</rptOwnerCik>
            <rptOwnerName>Feehan Michael</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ECOVYST INC.</rptOwnerStreet1>
            <rptOwnerStreet2>300 LINDENWOOD DRIVE</rptOwnerStreet2>
            <rptOwnerCity>MALVERN</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19355</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>See Remarks</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-08-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>16000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.2839</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>364799</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price.  These shares were purchased in multiple transactions at prices ranging from $6.265 to $6.29 inclusive.  The reporting person undertakes to provide to Ecovyst Inc., any security holder of Ecovyst Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price.</footnote>
    </footnotes>

    <remarks>Vice President and Chief Financial Officer</remarks>

    <ownerSignature>
        <signatureName>/s/ Joseph S. Koscinski, as attorney-in-fact for Michael Feehan</signatureName>
        <signatureDate>2024-08-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
