Interfacial Active-Oxygen Transport in Inverse CuO _x /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 LaMn 0.6 Cu 0.4 O 3 (LMCO) perovskite is integrated with CuO x -derived phases to form 80Cu-LMCO. The catalyst reaches a T 90 of 60 °C for CO oxidation, outperforming conventional perovskite and copper oxide catalysts under comparable conditions. Unlike previously reported CuO x or perovskite catalysts, this system uses an inverse CuO x /perovskite architecture to spatially separate O 2 activation from CO adsorption while coupling these processes through interfacial active-oxygen transport. In situ spectroscopy, 18 O 2 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.