Fully Amorphous Cerium/Carbon-Doped Manganese Oxides with Tailor-Made Pore and Electronic Properties for Superior Catalytic Ozone Decomposition

Metal oxides are promising for catalytic ozone (O3) decomposition to tackle the O3 pollution problem. However, reported metal oxides for O3 decomposition are predominantly crystalline and often suffer from low active site exposure and easy deactivation. Here, fully amorphous Ce/C-doped Mn2O3 materials with tailor-made macro-mesopores and electronic properties are developed. The synthesis is enabled by forming amorphous metal–organic coordination composites between histidine and atomically mixed metal ions, which are thermally converted to hierarchically porous amorphous Mn2O3 due to the Ce/C doping in the Mn2O3 skeleton and the self-bubbling and reductive roles of histidine. They demonstrate superior activity and stability in O3 decomposition under wide relative humidity (RH, 0–80%), capable of completely eliminating 50 ppm O3 for >25 h at 60% RH and a high velocity of 600 L g–1 h–1. Spectroscopic and theoretical studies unravel the structure–performance correlation and reaction mechanism. The superior performance originates from the amorphous Mn2O3 providing rich Mn3+ sites and a high surface area for O3 adsorption and activation, the Ce/C doping for promoting suitable electron transfer and inhibiting H2O and O22– accumulation, and the macro-mesopore structure for enhancing mass transfer and weakening H2O adsorption and condensation.