13/09/2018
Cover art depicting the atomic structure of a single-atom alloy featuring a methane molecule after C-H bond activation.
The next issue of The Journal of Physical Chemistry Letters will feature cover art from the perspective article ‘Lonely Atoms with Special Gifts: Breaking Linear Scaling Relationships in Heterogeneous Catalysis with Single-Atom Alloys’ by Matthew T. Darby, Michail Stamatakis, Angelos Michaelides, and E. Charles H. Sykes. The cover depicts the atomic structure of a so-called single-atom alloy, which is bimetallic alloy with a low concentration of the catalytically active component. One of these active sites prominently features a methane molecule after C-H bond activation. Dispersing the active component offers potential for well-defined and enhanced catalytic performance. View the full cover page here.
We discuss a simple yet effective strategy for escaping traditional linear scaling relations in heterogeneous catalysis with highly dilute bimetallic alloys known as single-atom alloys (SAAs). These systems, in which a reactive metal is atomically dispersed in a less reactive host, were first demonstrated with the techniques of surface science to be active and selective for hydrogenation reactions. Informed by these early results, PdCu and PtCu SAA nanoparticle hydrogenation catalysts were shown to work under industrially relevant conditions. To efficiently survey the many potential metal combinations and reactions, simulation is crucial for making predictions about reactivity and guiding experimental focus on the most promising candidate materials. This recent work reveals that the high surface chemical heterogeneity of SAAs can result in significant deviations from Brønsted−Evans−Polanyi scaling relationships for many key reaction steps. These recent insights into SAAs and their ability to break linear scaling relations motivate discovery of novel alloy catalysts.