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.

中文翻译：

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镍泡沫支撑的分层纳米结构镍钴合金作为肼氧化的高效电催化剂

用于肼氧化反应（HzOR）的高性能且非贵重的电催化剂的合成对于开发直接肼燃料电池（DHFC）作为便携式或车辆应用中的可行技术至关重要。在本文中，我们报道了使用水热法与两步煅烧相结合的方法，该方法轻松合成了具有海胆状分层纳米结构的镍泡沫（NF）负载的镍钴合金催化剂。这种自支撑电催化剂的精心设计和构造可以同时优化内在活性，提供丰富的可利用活性位点，确保良好的电导率，并促进反应物和气态产物的质量转移。因此，在最佳条件下制备的Ni-Co / NF催化剂表现出1213 mA cm的极高活性^-2在0.30 V与RHE，-0.16 V相对于RHE为HzOR，良好的耐久性，和四电子通路以下接近100％选择性朝向HzOR的低开始电位，表现优于DHFCs的阳极电迄今报道。