Exhibit 21.1

SUBSIDIARIES OF ECOVYST INC.

ENTITY						JURISDICTION
Ecovyst Inc.						Delaware
Ecovyst Holdings Inc.						Delaware
Ecovyst Midco I Inc.						Delaware
Ecovyst Midco II Inc.						Delaware
Ecovyst Catalyst Technologies LLC						Pennsylvania
Delpen Corporation						Delaware
Eco Services Operations Corp.						Delaware
Chem32 LLC						Delaware
Commercial Research Associates, Inc.						Pennsylvania
Zeolyst International1						Kansas
Ecovyst International Holdings Inc.						Delaware
New Dutch Catalyst Holdco 1 B.V.						Netherlands
New Dutch Catalyst Holdco 2 B.V.						Netherlands
New Dutch Catalyst Holdco 3 B.V.						Netherlands
Ecovyst Catalyst Technologies UK Ltd						United Kingdom
Ecovyst Zeolites B.V.						Netherlands
Zeolyst CV2						Netherlands
Ecovyst Catalyst Technologies Brazil Ltda						Brazil
PT Ecovyst Indonesia3						Indonesia
Ecovyst International Cooperatie UA						Netherlands
Ecovyst International B.V.						Netherlands
Ecovyst International, Inc.						Pennsylvania
Ecovyst Systems Inc.						Pennsylvania
Ecovyst Pennsylvania Inc.						Pennsylvania
Ecovyst UK Holding 1 Limited						United Kingdom
Ecovyst UK Holding 2 Limited						United Kingdom

1			Represents a joint venture company of which the registrant indirectly owns 50% of the voting equity.
2			Represents a joint venture company of which the registrant indirectly owns 50% of the voting equity.
3			Registrant indirectly owns 99.88% of the voting equity.