(52a) Escaping Linear Scaling Relations: Catalysis Beyond Constraints on Single Atom Alloys

Stamatakis, M. - Presenter, University College London
Darby, M., University College London
Michaelides, A., University College London
A single atom alloy (SAA) is manufactured by combining a host metal with a dopant metal at such high dilutions that the dopant remains atomically dispersed. The dopant atoms in such alloys are subject to electronic and geometric effects, giving rise to catalytic sites with unique properties, not exhibited by either component of the alloy in the monometallic state. This behavior in turn generates novel opportunities for designing catalysts for industrially relevant chemistries such as methane activation, ammonia dissociation or hydrogenation reactions. A fundamental understanding of the properties of SAAs would be indispensable in formulating principles that would aid catalyst design efforts.

Motivated by these opportunities, we discuss our latest research that aims at advancing our theoretical understanding of SAAs. By calculating the energies of adsorption and bond activation for key species participating in small-molecule chemistries, we investigate pertinent reactivity trends for dissociation reactions such as C-H, C-O, N-H, and H-H, on SAAs. These materials are thus found to escape traditional Brønsted-Evans-Polanyi relations, an effect caused by the decoupling of the energies of the transition state versus the initial/final states. Our results are discussed in the context of experimental findings on C-H and H-H bond activation, showcasing the importance and benefits of these materials.