Design and synthesis of Co@NiSe catalyst for efficient 2e− ORR in neutral electrolyte: Effect of electronic structure engineering

Abstract

Two-electron oxygen reduction reaction (2e⁻ ORR) generating hydrogen peroxide (H₂O₂) in neutral electrolytes is currently encountering significant scientific challenges. Here, we adopted a direct electron transfer and defect engineering approach for synthesizing a Co-doped NiSe hybrid catalyst to boost the efficiency of this reaction system. The Co@NiSe catalyst with long-term stability over 160 h showed a 53.1 % increase in H₂O₂ selectivity comparing with the pristine NiSe material in neutral electrolyte, indicating the effective modulation of the electronic structure of NiSe via Co doping. Impressively, the 2e⁻ ORR catalytic activity of the catalysts exhibited a positive linear dependence on the content of Ni²⁺ species. The present research proved the possibility for improving the activity of transition metal-based catalysts in neutral electrolytes via hetero-atom doping, which had built basic structure-function relations for designing highly efficient 2e⁻ ORR system.