Interfacial Active-Oxygen Transport in Inverse CuOx/Perovskite Catalysts for Low-Temperature CO Oxidation

Developing earth-abundant catalysts for low-temperature carbon monoxide (CO) oxidation is important for next-generation emission control, particularly in industrial scenarios where precious-metal catalysts face cost and stability constraints. Here, we report an “inverse” catalyst architecture in which LaMn0.6Cu0.4O3 (LMCO) perovskite is integrated with CuOx-derived phases to form 80Cu-LMCO. The catalyst reaches a T90 of 60 °C for CO oxidation, outperforming conventional perovskite and copper oxide catalysts under comparable conditions. Unlike previously reported CuOx or perovskite catalysts, this system uses an inverse CuOx/perovskite architecture to spatially separate O2 activation from CO adsorption while coupling these processes through interfacial active-oxygen transport. In situ spectroscopy, 18O2 isotopic-exchange experiments, and density functional theory (DFT) calculations further support this pathway by showing that LMCO activates oxygen and provides labile oxygen species, whereas reduced Cu-containing phases provide CO adsorption sites and mediate oxygen transfer toward interfacial Cu+ species. This active-oxygen transport pathway provides a mechanistic basis for designing robust, low-cost catalysts for low-temperature oxidation reactions.