A Molecular Catalyst-Like Oxide with Strong Redox Capability for Electrocatalysis

Abstract

Molecular catalysts can mediate fast and selective redox reactions under working conditions due to the flexible and adjustable coordination environment of their metal active centers. Therefore, the exploration of inorganic materials with structural and functional similarities to gifted molecular catalysts undoubtedly holds promise for highly active heterogeneous catalysts. Here, we report, for the first time, a molecular-like transition metal oxide, Mn₂V₂O₇, whose coordination environment of the active Mn sites resembles that of a molecular polyoxometalate (POM) catalyst. We emphasize that Mn₂V₂O₇ features strong redox capability, metal–oxygen covalency, and spin selectivity during catalytic reactions. These molecular-like functional properties have never been achieved in inorganic oxide materials and significantly boost the oxygen reduction reaction (ORR) activity of the Mn₂V₂O₇ catalyst, which is among the most active oxide catalysts ever reported. Moreover, the Mn₂V₂O₇-assembled Zn–air battery shows an ultrahigh peak power density of 455 mW cm^–2 with reliable charging over 1000 cycles, outperforming the ever-reported state-of-the-art metal oxide, metal, and carbon catalyst-based devices.