Constructing CuO/Co3O4 Catalysts with Abundant Oxygen Vacancies to Achieve the Efficient Catalytic Oxidation of Ethyl Acetate

The construction of multicomponent transition metal oxide catalysts can effectively increase the surface defects of catalysts, and bring a synergistic effect from different components, thus enhancing the generation of reactive oxygen species and improving the catalytic activity of catalysts for volatile organic compounds (VOCs) oxidation. In this article, CuO/Co3O4 catalysts with abundant oxygen vacancies for the degradation of ethyl acetate was prepared by a simple impregnation method. The effect of the ratio of Co/Cu on the redox capacity, oxygen vacancy, active oxygen species and catalytic oxidation activity of ethyl acetate were studied. The 90% conversion and mineralization temperatures of ethyl acetate for the optimal catalyst Co3O4-20Cu are 211 and 214 °C (WHSV = 60,000 mL/(g·h), 1000 ppm ethyl acetate), which also shows good stability and excellent water vapor resistance. Compared with pure Co3O4, the CuO/Co3O4 catalysts have more oxygen vacancies, provide more reactive oxygen species, allowing the catalyst better low-temperature reduction. Through in situ DRIFTS study, the intermediates of ethyl acetate decomposition were analyzed, then a possible catalytic oxidation mechanism of ethyl acetate on the Co3O4-20Cu catalyst was proposed. In addition, we prepared a Co3O4-20Cu/cordierite monolithic catalyst on the basis of Co3O4-20Cu, exhibiting a good catalytic activity in degradation of ethyl acetate.