Hierarchically Nanostructured Nickel-Cobalt Alloy Supported on Nickel Foam as a Highly Efficient Electrocatalyst for Hydrazine Oxidation

作者：Tang, Piao-Ping; Lin, Xi; Yin, Hui; Zhang, Deng-Xue; Wen, He; Wang, Jia-Jun; Wang, Ping^*

来源：ACS Sustainable Chemistry & Engineering, 2020, 8(44): 16583-16590.

DOI：10.1021/acssuschemeng.0c05846

• electrocatalyst
• direct hydrazine fuel cell
• hydrazine oxidation reaction
• earth-abundant catalyst
• Ni-Co alloy
• hierarchical nanostructure

Synthesis of high-performance and nonprecious electrocatalysts for the hydrazine oxidation reaction (HzOR) is of vital importance for the development of direct hydrazine fuel cells (DHFCs) as a viable technology for portable or vehicular applications. Herein, we report a facile synthesis of a Ni foam (NF)-supported Ni-Co alloy catalyst with an urchin-like hierarchical nanostructure using a hydrothermal method combined with two-step calcination. The elaborate design and construction of such a self-supported electrocatalyst can simultaneously optimize the intrinsic activity, afford abundant accessible active sites, ensure good electrical conductivity, and facilitate the mass transfer of reactants and gaseous products. As a consequence, the Ni-Co/NF catalyst prepared under optimal conditions exhibited an exceptionally high activity of 1213 mA cm(-2) at +0.30 V versus RHE, a low onset potential of -0.16 V versus RHE for the HzOR, good durability, and nearly 100% selectivity toward the HzOR following the four-electron pathway, outperforming the anode electrocatalysts of DHFCs hitherto reported.