Business Description

Ecovyst Inc. (“Ecovyst” or the “Company”), formerly PQ Group Holdings Inc., was incorporated in Delaware on August 7, 2015. We trace our roots to the late 1800s with our first sulfuric acid plant and the beginning of our oldest customer relationship. Our common stock is listed on the New York Stock Exchange under the stock ticker “ECVT”. Unless the context otherwise indicates, the terms “Ecovyst Inc.,” “we,” “us,” “our,” or the “Company” mean Ecovyst Inc. and our subsidiaries. Effective on December 31, 2025, we completed the sale of our Advanced Materials & Catalysts segment, which includes our investment in affiliated companies, Zeolyst International and Zeolyst C.V. (collectively, the “Zeolyst Joint Venture”) to Technip Energies N.V. for a purchase price of $556.0 million, subject to certain adjustments set forth in the agreement. We used $465.0 million of the net cash proceeds to partially repay the Senior Secured Term Loan Facility due June 2031. The results of operations, financial condition and cash flows for the Advanced Materials & Catalysts business are presented herein as discontinued operations. Refer to Note 4 to our consolidated financial statements for additional information. Our Company We are a leading integrated provider of virgin and regenerated sulfuric acid products and services. We believe that our business contributes to improving the sustainability of the environment. We are a leader in our business, holding what we estimate to be a number one or number two supply share position for products and services that generated more than 95% of our 2025 sales. We believe that our footprint and efficient network of strategically located manufacturing and regeneration facilities provide us with a strong competitive advantage in serving our customers. Our products and services typically represent a small portion of our customers’ overall end-product costs, yet are critical to their processes. With our long history of customer partnerships and our reputation for providing reliable, quality products and services, we believe we deliver significant value to our customers, as demonstrated by our profit margins. We are diversified by business application and end use. In 2025, the majority of our sales were for applications that have historically had relatively predictable, consistent demand patterns associated with consumption and industrial processes. As a result of our competitive strengths, we have generally maintained stable earnings and margins over time and through changing macro economic cycles. In 2025, we served customers across many end uses and, as of December 31, 2025, operated out of nine strategically located manufacturing facilities. Our Strategy We intend to capitalize on our strong business fundamentals and long-term customer partnerships to grow sales, maintain high margins, deploy capital efficiently and generate consistent free cash flow in order to create stockholder value. We believe that our long history of operational excellence and proven reliability, longstanding customer relationships, a network of strategically located manufacturing facilities and consistent business execution developed from our industry experience positions us well to execute our business strategy. Our Industry The products and services that we provide to our customers are often high value-add, even when they represent a small portion of our customers’ overall end product costs, and we believe we can continue to be successful by providing customers with quality products and reliable service. We believe many of the end uses that we serve are generally more resilient to economic cycles, minimizing extreme fluctuations in demand. We believe our customers value our geographic proximity to their operations and our plant network provides redundancy in capacity to serve their needs. We believe the combination of attractive operating margins and generally predictable maintenance capital expenditure requirements improves our ability to generate attractive cash flows. 3 Table of Contents Our Product End Uses The table below summarizes our key end use applications and products, as well as the significant growth drivers in those applications.…