Significant Improvement of Catalytic Performance for Chlorinated Volatile Organic Compound Oxidation over RuOx Supported on Acid-Etched Co3O4

Ru catalysts have attracted increasing attention in catalytic oxidation of chlorinated volatile organic compounds (CVOCs). However, the development of Ru catalysts with high activity and thermal stability for CVOC oxidation still poses significant challenges due to their restrictive relationship. Herein, a strategy for constructing surface defects on Co₃O₄ support by acid etching was utilized to strengthen the interaction between active RuO_x species and the Co₃O₄ support. Consequently, both the dispersity and thermal stability of RuO_x species were significantly improved, achieving both high activity and stability of Ru catalysts for CVOC oxidation. The optimized Ru catalyst on the HF-etched Co₃O₄ support (Ru/Co₃O₄-F) achieved complete oxidation of vinyl chloride at 260 °C under 30 000 mL·g^-1·h^-1, which was lower than 300 °C for the Ru catalyst on the original Co₃O₄ (Ru/Co₃O₄). More importantly, the Ru species on the Ru/Co₃O₄-F catalyst were hardly lost after calcination at 500-700 °C and even reacting at 650 °C for 120 h. On this basis, the polychlorinated byproducts over the Ru/Co₃O₄-F catalyst were almost completely effaced by phosphate modification on the catalyst surface. These findings show that the method combining acid etching of the support and phosphate modification provides a strategy for the advancement of catalyst design for CVOC oxidation.