Document

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (Nos. 333-220774, 333-227643 and 333-262180) and the Registration Statement on Form S-3 (No. 333-255514) of Ecovyst Inc. of our report dated February 29, 2024 relating to the financial statements, financial statement schedule and effectiveness of internal control over financial reporting, which appears in this Form 10-K.