Highly efficient MnOx catalysts derived from Mn-MOFs for chlorobenzene oxidation: The influence of MOFs precursors, oxidant and doping of Ce metal

Abstract

In this research, we introduce a simple, effective, and eco-friendly approach for preparing MnOx materials with a hierarchical porous structure and apply it to the catalytic oxidation of chlorobenzene. In this method, different Mn-based MOFs are used as templates, and MnOx materials with various morphologies and structures are prepared through an alkaline hydrolysis-oxidation method. Different Mn-MOF precursors, oxidants and doping of different metals have a considerable influence on the structural morphology of the obtained MnOx materials. Through adjusting the structural morphology, it is conducive to transfer, diffusion and enrichment of chlorobenzene during the reaction process, and improving the reaction activity. MnO2-74 catalyst derived from Mn-MOF-74 in the presence of H2O2 showed the best catalytic activity (T90 = 174 °C). The exceptional catalytic efficiency is attributed to its large specific surface area, mesoporous structure, better low-temperature reducibility, sufficient acidic sites, and enhanced oxygen activation ability. The primary cause of the decrease in catalytic activity is the existence of surface carbon and inorganic chlorine on the catalyst. This green, efficient, and economical preparation method introduces a novel strategy for the traditional derivatization of MOFs to prepare metal oxide materials for the catalytic oxidation of chlorinated volatile organic compounds (CVOCs).