Synthesis of Co-N-C grafted on well-dispersed MnOx-CeO2 hollow mesoporous sphere with efficient catalytic performance

Abstract

Metal oxide hollow sphere have emerged as a kind of promising nanostructured materials for catalysis, energy conversion, and storage capacity. Herein, a “silica-protective-layer-assisted” approach is adopted to synthesize Co-N-C supported MnOx-CeO2 hollow mesoporous spheres, which can effectively suppress the sintering of metal oxide. The metal oxide hollow mesoporous spheres are prepared through silica template, MnOx-CeO2 shell, cobalt porphyrin precursor, and silica protective layer via a layer-by-layer strategy. The Co-N-C/MnOx-CeO2 catalysts show a remarkable catalytic performance for the oxidation of ethylbenzene (ethylbenzene conversion to 44.5%). Moreover, the catalysts have well-defined morphology, homogeneously dispersed, high specific surface area and porous structure. The enhanced catalytic performance is attributed to the hollow hierarchically mesoporous structure and the synergistic effect between oxygen vacancy and Co-Nx active sites derived from the pyrolysis of cobalt-N4 macrocycles of cobalt porphyrin.