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. [Display omitted] •Synergy of Cr2O3 and RuO2/TiO2 remarkably promotes 1,2-DCE deep destruction.•Cr2O3 promotes the generation of Ru4+ sites and active oxygen species.•1,2-DCE primarily activates on the Lewis acid sites with C-C and C-Cl cleavage.•Cr2O3 improves the Lewis acid site concentration and inhibits by-product formation.•RuO2/Cr2O3/TiO2 composite has high stability toward H2O, SO2, and chlorine species.