The effect of CuO loading on different method prepared CeO2 catalyst for toluene oxidation

The support effect on CeO2 supported CuO catalysts are extensively investigated, but few studies have been reported in volatile organic compounds (VOCs) oxidation. Herein, CuO was impregnated on three conventional method synthesized CeO2 to study its impact on toluene total oxidation over CeO2 at low temperature (<= 280 degrees C). Characterization results demonstrated that the shape and specific surface area of CeO2 affected the degree of CuO dispersion, which determine the interaction between CuO and CeO2. CuO significantly enhanced the toluene adsorption capacity of CeO2, but lots of oxygen vacancies were lost during its loading. Although strong Cu-Ce interaction induced new oxygen vacancies, the increase or decrease of final amount was related to the original surface properties of CeO2. Mechanism analysis suggested that the activation of oxygen on oxygen vacancies controlled the toluene oxidation reaction rate. Therefore, the promotion or inhibition effect of CuO on CeO2 for toluene oxidation depends on physical and chemical properties. Through this study, we have drawn some valuable information in guiding the synthesis and design of CuO-CeO2 based catalysts. (C) 2019 Published by Elsevier B.V.