Dynamic variations of metal-O bonding in electro- and thermo-catalytic activation processes

Dynamically tracking the variations in electronic configurations and molecular binding of a catalyst under operando conditions remains a significant challenge. Herein, we report an in-situ millisecond-resolved wide-angle X-ray scattering technique to capture lattice distortion within a catalyst in low-temperature oxidation under electric- and thermal-induced catalysis and reveal the intrinsic mechanism of metal-O bonding on oxygen activation and the electro promotion. The c-directional lattice spacing of MnO2 loaded on Ni foam is observed to undergo contraction and recovery processes with and without a direct electric field, respectively. Hard and soft X-ray absorption fine structure spectra, density functional theory and temperature-programmed reduction analyses confirm that an external current can effectively modulate the electronic configuration of manganese and oxygen atoms in the MnO2 catalyst and alter the covalent bonding between Mn and O atoms by weakening the Mn-O bond, thereby enhancing the activity of lattice oxygen in the catalyst. This study provides scientific insights into the dynamic evolution of lattice distortion in externally field-induced catalytic reactions. Dynamically tracking changes in a catalyst’s electronic configurations and molecular binding under operando conditions remain challenging. Here, the authors use millisecond-resolved in situ wide-angle X-ray scattering to capture lattice distortions, revealing how metal–O bonding drives oxygen activation and electro-promotion.