A novel wormhole-like mesoporous hybrid MnCoOx catalyst for improved ethanol catalytic oxidation

Abstract

A series of wormhole-like mesoporous hybrid MnCoOx catalysts have been successfully prepared using a soft template combining the sol-gel method. The physical and chemical properties of these mesostructured materials are systematically characterized using XRD, BET, Raman, XPS, HRTEM, H2-TPR and O2-TPD and compared with pure MnOx and Co3O4. Their catalytic performances for ethanol oxidation are investigated and carried out on a fixed-bed reactor. It is found that the molar ratio of transition metal precursors has a remarkable influence on the nanoparticle morphology, open-framework structure dispersion, surface element distribution, and redox property. Among the MnCoOx catalysts, Mn1Co1 catalyst composed by uniform worm-like nanoparticles shows the highest BET surface area (208 m2/g), most surface proportion of Co3+ and Mn4+ (18.7%), lowest reducibility potential and best catalytic activity (T50 = 80 °C) as well as an excellent CO2 selectivity (S170 = 100%) with a GHSV of 60,000 mL·(g·h)−1. Based on the structure-function analysis of catalysts, it is deduced that the synergistic effect between Mn and Co in MnxCo1−xOy solid solution and proton scavenger addition in preparation can improve the mesostructured, active sites distribution and catalytic performance. Consequently, it can be expected that the mesoporous hybrid MnCoOx catalysts are promising materials for catalytic removal of VOCs, and the related results in this research would also provide some new insights into the porous composite material design and application exploration for ethanol catalytic oxidation.