Oxide Interface-Stabilized Superoxo Species for High-Temperature Catalysis

High-temperature oxidation reactions catalyzed by earth-abundant transition metal oxides are vital for numerous industrial and environmental processes. However, their performance is often limited by the rapid desorption of active oxygen species at high temperatures. Here, we describe a straightforward approach to constructing a CuMn spinel/Mn2O3 composite oxide catalyst that addresses this limitation and demonstrate that lattice oxygen can spontaneously migrate to form interface-stabilized superoxo species under high-temperature reaction conditions. This catalyst exhibits a 14-fold enhancement in the CH4 oxidation reaction compared to Mn2O3, with activity and stability even better than those of many reported noble-metal supported catalysts. In situ characterizations and theoretical calculations reveal that the superoxo species accept electrons from the neighboring Cu and Mn atoms, exhibiting enhanced ability for C-H activation. This work illustrates the critical role of interface-stabilized superoxo species in CH4 oxidation and establishes a promising route for promoting high-temperature catalytic processes through interface engineering.