Catalytic oxidation of ethyl acetate and toluene over Cu-Ce-Zr supported ZSM-5/TiO2 catalysts

Copper-cerium-zirconium catalysts loaded on ZSM-5/TiO2 (denoted as CCZ/Z and CCZ/T) were prepared and characterized in this investigation and the catalytic behaviors of VOCs over the catalysts were determined. It is shown that the low-temperature activities of ethyl acetate and toluene oxidation over the CCZ/T catalyst are obviously higher than that over the CCZ/Z catalyst. Compared with CCZ/Z, the force between the metal oxides and the support TiO2 is weaker and TiO2 can provide some lattice oxygen. The greater number of oxygen vacancies, together with more Cu+ species in CCZ/T increases the mobility of atomic oxygen anions, which can inhibit by-product formation and enhance catalytic activity effectively. Moreover, the larger pore size of CCZ/T is beneficial for the diffusion of reactants and products. The analysis of intermediate species and the Mars-van Krevelen mechanism well explain the superior oxidation performances of ethyl acetate and toluene on CCZ/T. Both CCZ/Z and CCZ/T show superior stability for the catalytic removal of ethyl acetate and toluene at their complete conversion temperatures, which contribute to the positive effects of the Ce-Zr promoters on the copper species and support.