Electrolytic overall water splitting is a promising approach to produce H2 , but its efficiency is severely limited by the sluggish kinetics of the oxygen evolution reaction (OER) and the low activity of current electrocatalysts. To solve these problems, in addition to the development of efficient precious-metal catalysts, an effective strategy is proposed to replace the OER by the selective methanol oxidation reaction. Ni-Co hydroxide [Nix Co1-x (OH)2 ] nanoarrays were obtained through a facile hydrothermal treatment as the bifunctional electrocatalysts for the co-electrolysis of methanol/water to produce H2 and value-added formate simultaneously. The electrocatalyst could catalyze selective methanol oxidation (≈1.32 V) with a significantly lower energy consumption (≈0.2 V less) than OER. Importantly, methanol was transformed exclusively to value-added formate with a high Faradaic efficiency (selectivity) close to 100 %. Specifically, a cell voltage of only approximately 1.5 V was required to generate a current density of 10 mA cm-2 . Furthermore, the Ni0.33 Co0.67 (OH)2 /Ni foam nanoneedle arrays presented an outstanding stability for overall co-electrolysis.

中文翻译：

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通过选择性甲醇氧化作为阳极反应提高电化学氢热电联产的增值甲酸盐生产。

电解总水分解法是生产H2的一种有前途的方法，但是其效率受到制氧反应（OER）的动力学缓慢和当前电催化剂活性低的严重限制。为了解决这些问题，除了开发有效的贵金属催化剂以外，还提出了一种通过选择性甲醇氧化反应代替OER的有效策略。通过便捷的水热处理获得了Ni-Co氢氧化物[Nix Co1-x（OH）2]纳米阵列，将其作为双功能电催化剂，用于甲醇/水的共电解，同时生成H2和增值的甲酸盐。与OER相比，电催化剂可以催化选择性的甲醇氧化（约1.32 V），而能耗要低得多（约0.2 V）。重要的，甲醇仅以接近100％的高法拉第效率（选择性）转化为高附加值的甲酸盐。具体而言，仅需要大约1.5 V的电池电压即可产生10 mA cm-2的电流密度。此外，Ni0.33 Co0.67（OH）2 / Ni泡沫纳米针阵列为整体共电解提供了出色的稳定性。