Catalytic mechanism study on manganese oxide in the catalytic supercritical water oxidation of nitrobenzene

摘要

Among all the transition metal oxides, MnO2, which exhibits stable performance in supercritical water oxidation (SCWO), has a relatively high catalytic activity in the catalytic decomposition of organic compounds by oxidation. Hence, for some organics that are difficult to degrade, MnO2 is a commonly used catalyst. However, the mechanism of the catalytic oxidation of organic compounds by a manganese oxide catalyst is not very clear. In this study, the catalytic mechanism of manganese oxide in the supercritical water oxidation of nitrobenzene was discussed via TG-MS, XRD, activity tests and product analysis. In the process of supercritical water oxidation, the catalyst exists in a mixed MnO2-Mn2O3 state, in the role of an electron relay that promotes the generation of strong oxidizing agents ((OH)-O-center dot, O*) and the catalytic oxidation of nitrobenzene.