Sea-urchin-like mesoporous copper-manganese oxide catalysts: Influence of copper on benzene oxidation

Mesoporous copper manganese oxides were prepared via a simple method to be used for the catalytic oxidation of benzene emitted from industrial activities. Morphological characterization revealed that the primary particles of the as-synthesized catalysts were nanorods that aggregated with each other to form sea-urchin like structures. Compared with the manganese oxide based catalyst, copper manganese oxides exhibited better performances for benzene oxidation, achieving the best benzene conversion rate of 90% at around 219 degrees C, which is 23 degrees C lower than that for the catalyst without copper. The benefit of copper addition exists because the addition of copper in the manganese oxide causes desorption of lattice oxygen, increasing concentrations of oxygen defects on the catalyst surfaces. Furthermore, the addition of copper was found to contribute to the increase in the specific surface area by reducing the sizes of the nanorods and sea-urchin structures. Finally, the influential factors for catalytic oxidation were oxygen vacancies and the oxidation state of metals. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.