Tuning the water resistance of Co₃O₄ catalysts via Ce incorporation for enhanced catalytic oxidation of toluene

It is important to design and develop catalysts with good water resistance to cope with the toxicity of water vapor on catalyst activity. In this study, we proposed a simple method to improve the water resistance of catalysts for toluene catalytic combustion by preparing a series of Co-Ce composite oxide catalysts via a citrate sol–gel method. Experimental results showed that Co₆Ce₁O_x exhibited the best catalytic activity (T₅₀ = 236 ℃ T₉₀ = 251 ℃) and water resistance among all the catalysts. The crystal structure and surface chemistry of the catalysts were analyzed using a series of correlation characterizations, and the adsorption energies of toluene and water on the catalysts were calculated using density functional theory (DFT). The results showed that the doping of Ce in Co₃O₄ had not only effectively changed the oxygen distribution state of Co₃O₄ and increased its oxygen vacancy content, thus greatly enhancing the oxidizing ability of the catalyst, but also suppressed the adsorption of H₂O on the surface of the catalyst, and significantly enhanced the water resistance of the catalyst. The present work provided a new idea and method for developing efficient and excellent water resistant catalysts for the catalytic oxidation of toluene.