Single-atom alloys (SAAs) show high catalytic activity and selectivity, escaping traditional predictive frameworks. This study, based on thousands of DFT calculations, reveals a 10-electron count rule for adsorbate binding on SAA dopant atoms. A molecular-orbital approach explains this rule and the adsorbate-dopant interaction. This intuitive model accelerates SAA catalyst design, as illustrated by identifying promising dopants for hydrogenation reactions, significantly reducing potential material candidates.

Julia Schumann, Michail Stamatakis, Angelos Michaelides, Romain Réocreux