Formulating electronic descriptors to rationally design graphene-supported single-atom catalysts for oxygen electrocatalysis

Graphene-supported single-atom catalysts (G-SACs) have attracted considerable attention as promising candidates for oxygen electrocatalysis because of their low use of precious metals. However, the low specific activity resulting from insufficient intrinsic catalytic activity and the agglomeration of single atoms are challenges inhibiting the wide use of G-SACs. To solve these problems, this study provides a rational design method for G-SACs in terms of their electronic structure. By investigating the relationship between the electronic structure of G-SACs and their catalytic performance, we revealed that the frontier orbitals of the active single atoms and the Fermi level of G-SACs are effective descriptors determining the intrinsic activity and stability against agglomeration, respectively. Furthermore, we demonstrate that these two descriptors are appropriate for the rational design of G-SACs by confirming the effect of doping on a Cu-N-C catalyst, and we suggest controlling these powerful descriptors as a guideline for material design.