Mn/Co bimetallic MOF-derived hexagonal multilayered oxide catalysts with rich interface defects for propane total oxidation: Characterization, catalytic performance and DFT calculation

Abstract

Several hexagonal layered Mn/Co oxide catalysts were synthesized from Mn/Co-based metal–organic framework (MOF) precursors. The molar ratio of Mn/Co affects the physicochemical properties of catalysts, further affects their catalytic performance. The Mn/CoOx-3/2 sample with wide interlayer spacing exhibited the highest catalytic activity for total oxidation of propane, with a T90 of 270 °C at 120 L g−1 h−1. Low-temperature reducibility, oxygen mobility, water vapor tolerance, and oxygen defects play the key roles for improving catalytic activity. Oxygen defects were calculated using the density functional theory (DFT). The results show that the doping of Mn on Co oxide is conducive to the formation of oxygen vacancies. Therefore, benefiting from the layered structure and metal-doping for the catalysts, the formation of more abundant interfacial defects can further improve the catalytic performance. This study offers a simple way to synthesize regular layered multi-metal oxide, which can expose abundant interface defects and active sites.