Cerium decorated amorphous ternary Ni-Ce-B catalyst for enhanced electrocatalytic water oxidation

Metal borides have been acknowledged as promising candidates for alkaline oxygen evolution reaction (OER). Here, amorphous ternary metal borides (Ni-Ce-B) with different molar ratios of Ce% are achieved by a facile wet chemical method. With the optimal 5% of Ce, the as-prepared Ni-Ce-B-5/NF electrode exhibits comparable OER performance with lower overpotential (240 mV) than that of pure Ni-B/NF electrode (330 mV) and other metal borides. The high activity of Ni-Ce-B/NF is attributed to the amorphous structure and synergistic effect of binary metal Ni and Ce in Ni-Ce-B materials. Additionally, CeO2-x forms and serves as an electron acceptor during the self-electrooxidation process, facilitating the formation of crystalline high-valence nickel species, resulting in robust electrocatalysis and long-term stability. This work presents a Ce-based metal boride as a promising candidate for the low-cost and highly efficient OER catalyst.

Automated summary

Metal borides have shown potential as alkaline OER catalysts, with amorphous ternary Ni-Ce-B materials displaying superior performance when Ce content is optimized at 5%. The enhanced activity of Ni-Ce-B/NF electrodes is attributed to the synergistic effect between Ni and Ce, as well as the role of CeO2-x in promoting the formation of high-valence nickel species during self-electrooxidation. This study highlights Ce-based metal borides as promising candidates for low-cost and efficient OER catalysis.