Electrodeposited NiCu nanoparticles for the borohydride oxidation reaction: Effect of Cu on the activity and stability of Ni upon surface oxidation

• Published in: Electrochimica acta 2022-11, Vol.433, p.141196, Article 141196
• Main Authors: Vorms, Evgeniia A., Suprun, Evgeniy A., Nartova, Anna V., Kvon, Ren I., Oshchepkov, Alexandr G.
• Format: Article
• Language: English
• Subjects: Alkaline media; Borohydride oxidation reaction (BOR); Copper; Electrodeposition; Nickel
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2022.141196

•The composition of electrodeposited NiCu nanoparticles is controlled by the value of the deposition potential.•Metallic NiCu nanoparticles enriched with Ni show BOR activity comparable to metallic Ni.•NiCu nanoparticles demonstrate higher resistance against electrochemical oxidation and improved reducibility than Ni nanoparticles.•Surface oxidation at mild conditions results in a significant decrease of BOR currents on Ni, but slightly affects the performance of NiCu nanoparticles of certain compositions. Development cost-effective and stable electrocatalysts for the borohydride oxidation reaction (BOR) is mandatory for the deployment of the direct borohydride fuel cells (DBFC). Ni electrocatalysts have recently been shown to outperform noble-metal (Pt, Pd, Au) catalysts at low BOR overpotentials, but their activity largely depends on the state of the Ni surface with metallic Ni demonstrating the highest activity. Here, bimetallic NiCu nanoparticles of different compositions were prepared, which demonstrate high BOR activity comparable to Ni nanoparticles in the metallic state of their surface and allow to overcome in considerable extent the negative issues related to inevitable surface passivation.