Composition regulation of nickel selenide and its effects on the catalytic activity in the oxygen reduction reaction

Abstract

Excellent electrode materials are essential to promote the industrialization of new energy devices. Herein, five different nickel selenides were obtained by regulating the molar ratio of the raw materials and reaction temperature, and their oxygen reduction reaction (ORR) activities were systematically contrasted. Through the study of their composition, structure, morphology, and catalytic properties, the onset potentials of 0.98 V and 0.93 V (vs. RHE) exhibited the excellent ORR activity possessed by Ni_1−xSe and c-NiSe₂, which were close to that of Pt/C. In addition, their durability and methanol tolerance were far better than those of Pt/C. Their surfaces undergo an ORR process dominated by a 4-electron pathway. The present research provides a novel approach to explore suitable low-cost catalytic materials to replace Pt/C for the industrialization of fuel cells.