Construction of dual-functional sites via Ru pre-loading on (VO_x)_n/CeO₂ for multi-pollutant control

Vanadium-ceria catalysts have become promising bifunctional catalysts for simultaneously removing nitrogen oxides (NO_x) and chlorobenzene (CB). However, limited selectivity toward inorganic chlorine species and the accumulation of chlorine species remain critical challenges. In this study, a Ru-modified (VO_x)_n/CeO₂ catalyst was synthesized via a pre-loading strategy. The pre-loaded Ru species not only created highly active redox sites favorable for deep CB oxidation through strong interactions with the CeO₂ support but also enhanced the polymerization of V species and modulated the electronic environment of V=O species, enhancing the selective catalytic reduction (SCR) activity and the ability to cleave C–Cl bonds. Importantly, the Ru pre-loading preserved Brønsted acid site concentrations while decreasing Lewis acid site density, thereby reducing Cl deposition and improving catalyst stability. As a result, the optimized catalyst demonstrated superior performance, achieving over 90% NO_x and CB conversion in the 330–400 °C temperature range. The selectivities towards inorganic chlorine species (IC) and CO_x are both maintained above 90%.