Exhibit 99.1 Ecovyst Reports Third Quarter 2024 Results MALVERN, PA, October 31, 2024 -- Ecovyst Inc. (NYSE: ECVT) ("Ecovyst" or the "Company"), a leading integrated and innovative global provider of advanced materials, specialty catalysts and services, today reported results for the third quarter ended September 30, 2024. Third Quarter 2024 Results & Highlights ▪ Sales of $179.2 million, compared to $173.3 million in the third quarter of 2023 ▪ Net Income of $14.3 million, compared to $16.6 million in the ...