Ceria-based oxide catalysts supported on metal–organic frameworks: selective oxidation of toluene to CO2 and the doped metal-activity relationship

Abstract

Controlling toluene emissions via catalytic oxidation necessitates catalysts with high redox performance. Construction of active centers with large specific surface areas towards reactants is a prerequisite for developing such catalysts. Herein, using a highly crystalline metal–organic framework (MOF), UiO-66-Ce, we synthesized and investigated the oxidation catalytic properties of transition metal-doped CeO₂. Analytical and spectroscopic methods combined with X-ray diffraction were employed to determine the properties of materials (CeMO_x/UiO-66, M = Cu, Co, Mn, Fe, Zr). As a model reaction, the oxidation of toluene under oxygen was used to investigate catalytic properties. Various characterizations and in situ diffuse reflectance infrared Fourier transform spectroscopy confirmed that incorporation of Cu into CeO₂/UiO-66 increased the number of surface defects, thereby enhancing the catalytic activity further. Our research provides a strategy for the development of improved catalysts for toluene oxidation by MOF-loaded metal oxides.