A first-principle study of an alloy-supported single-atom catalyst for oxygen reduction reactions

The rational design of single atom catalysts with high activity is essential to improve the slow kinetics of the oxygen reduction reaction in metal-air batteries and proton exchange membrane fuel cells. Here, using the first-principles methods based on density functional theory (DFT), the oxygen reduction reactions of single-atom catalysts Co-N-C and Fe-N-C supported on Co 3 Fe alloys were further suggested as efficient ORR catalysts. The results indicate that the positions of the non-metallic atoms in the nitrogen-doped carbon are well adapted to the surface layer of the alloy. The overpotentials of the alloy-loaded catalysts are reduced from 0.63 V for Co-N-C and 0.81 V for Fe-N-C to 0.40 V and 0.31 V, respectively, compared with the 2D single atom catalysts. The origin of the activity stems from suitable coordination environments for cobalt and iron, crucially affecting the rate-determining step. This study identifies a new specific link between the alloy coordination environment and catalytic activity, with implications for catalyst design.