(41b) Design of Single-Atom Alloys for Oxidation

Single-atom alloys have shown strong catalytic performance for several types of reactions, including hydrogenation reactions and alkane conversion. However, single-atom alloys have not been extensively studied for oxidation reactions, despite the critical importance of these reactions. The possibility that single-atom alloys could easily activate molecular oxygen but bind O relatively weakly makes them intriguing, as weakly bound O is likely to be quite reactive. In this work, we computationally designed single-atom alloys for oxidation, focusing on surfaces that can easily activate O₂ but give relatively weak O binding. We found that several single atom alloys can activate O₂ with very low barriers, in some cases near 0, while still binding O relatively weakly. Subsequent experimental synthesis and testing of single-crystal single-atom alloy surfaces shows that single-atom alloys can activate O₂ and O can subsequently spillover onto the inert host sites. Finally, single-atom alloy nanoparticles were synthesized and tested, and show very high activity and selectivity for oxidation reactions. Extensive experimental studies, combined with detailed computations, give strong insight into the structure of the catalyst and the mechanism underlying the high performance. This work demonstrates the utility of integrated computational-experimental studies, and opens up the possibility of high-performance single-atom alloy catalysts for many oxidation reactions.