First-principles study on the catalytic performance of transition metal atom-doped CrSe₂ for the oxygen reduction...

Since the oxygen reduction reaction (ORR) is the cathodic reaction of energy storage and conversion devices such as fuel cells and metal-air batteries, the search for catalysts with high-performance toward ORR has become the focus of attention. Transition metal dichalcogenides (TMDs) have the advantages of easy integration, inexpensive, harmless, good stability, and have vast application prospects in stabilizing the single atom. Hence, in this study, we investigated the feasibility of several 4d/5d single transition metals (TM = Rh, Pd, Ag, Ir, Pt, and Au) doped with CrSe₂ for ORR electrocatalysis on the basis of density functional theory (DFT) calculations. Our results demonstrated that most of the TM-doped systems are stable, exhibiting metal conductivity, and can well activate the adsorbed O₂. Interestingly, compared with end-on adsorption configuration, O₂ is more likely to be adsorbed on the catalysts by a side-on adsorption configuration. Among all the candidate ORR catalysts, Pd-doped and Pt-doped CrSe₂ have the best catalytic performance with a low overpotential of 0.43 and 0.50 V, respectively, making them good ORR candidate high performance catalysts. Our DFT work helps to understand the interaction between the O₂ molecule and transition metal single atoms on CrSe₂ supports and provides ideas for designing stable and efficient ORR catalysts.