Inserting Cr₂O₃ dramatically promotes RuO₂/TiO₂ catalyst for low-temperature 1,2-dichloroethane deep destruction: Catalytic performance and synergy mechanism

Ru-based catalysts with increased attention for CVOC purification still have huge challenges in promoting their low-temperature activity and durability. Here, a Cr-modified RuO₂/TiO₂ catalyst was fabricated and employed for 1,2-dichloroethane (1,2-DCE) destruction. The synergy of Cr₂O₃ and RuO₂/TiO₂ enhances the exposure of surface Ru, generating abundant reducible Cr⁶⁺ and Ru⁴⁺ species and chemically adsorbed oxygen, which promote the activity and CO₂/HCl selectivity in 1,2-DCE decomposition evidently. 1,2-DCE primarily activates on the Lewis acid sites (LAS) over RuO₂/Cr₂O₃/TiO₂ with C-Cl cleavage. Meanwhile, C-C cleavage occurs along with the dehydrochlorination and chlorination reactions. The presence of Cr₂O₃ greatly improves the LAS concentration and redox ability of RuO₂/TiO₂, accelerating the deep destruction of 1,2-DCE and inhibiting the formation of CH₂Cl₂, C₂HCl₃ and CHCl₃. Cr species with superior chlorine resistance elevate the durability of RuO₂/Cr₂O₃/TiO₂ under simulated conditions toward H₂O, SO₂, and chlorine species, making it a promising candidate for industrial CVOC catalytic degradation.