A Supported Metal Dual-Atom Site Catalyst for Oxygen Reduction: A First-Principles Study

Abstract Dual-atom site catalysts with the adjacent metal atomic sites can cooperatively catalyze oxygen reduction reaction (ORR), showing great potential in ORR field. Herein, the ORR activity and mechanism of a supported metal dual-atom site catalyst M2-DAC (M is 3d transition metal) is explored thoroughly by density functional theory methods. By calculating Ed of M2-DAC, all structures are thermodynamically stable and are used for subsequent studies. Considering the adsorption of O2, total 6 kinds of M2-DAC are identified as potential candidate materials for catalyzing ORR due to their moderate adsorption of O2. The binding energy of ORR species and the change of Gibbs free energy in each step of ORR are calculated, and Co2-DAC exhibits notable catalytic activity (ηORR = 0.39 V). Moreover, the charge analysis of Co2-DAC shows that the ORR activity of the catalyst mainly comes from the metal atom and the O atoms coordinated with the metal atoms.