Theoretical insights into oxygen reduction reaction on Au-based single-atom alloy cluster catalysts

Developing highly active alloy catalysts that surpass the performance of platinum group metals in the oxygen reduction reaction (ORR) is critical in electrocatalysis. Gold-based single-atom alloy (AuSAA) clusters are gaining recognition as promising alternatives due to their potential for high activity. However, enhancing its activity of AuSAA clusters remains challenging due to limited insights into its actual active site in alkaline environments. Herein, we studied a variety of Au54M1 SAA cluster catalysts and revealed the operando formed MOx(OH)y complex acts as the crucial active site for catalyzing the ORR under the basic solution condition. The observed volcano plot indicates that Au54Co1, Au54M1, and Au54Ru1 clusters can be the optimal Au54M1 SAA cluster catalysts for the ORR. Our findings offer new insights into the actual active sites of AuSAA cluster catalysts, which will inform rational catalyst design in experimental settings.