PQ Group Holdings Inc. is a U.S.-based specialty chemicals company focused on catalysts and sulfuric acid services for the refining, petrochemical, and polymer industries. Originating from Philadelphia Quartz (PQ Corporation) and headquartered in Malvern, Pennsylvania, the company operates manufacturing and service facilities across North America, Europe, and Asia. In 2021, PQ Group Holdings rebranded as Ecovyst Inc.
Through its Catalyst Technologies business, the company supplies silica supports and silica- and zeolite-based catalysts used in polyolefin production and in refinery and petrochemical processes. Its Ecoservices business produces and regenerates sulfuric acid, serving alkylation units in fuel production and providing spent acid management and recycling services. PQ’s technologies are applied to improve process efficiency and product performance across fuels and industrial chemical value chains.