Electrochemical reduction of carbon dioxide (CO2 ) to CO is regarded as an efficient method to utilize the greenhouse gas CO2 , because the CO product can be further converted into high value-added chemicals via the Fisher-Tropsch process. Among all electrocatalysts used for CO2 -to-CO reduction, Au-based catalysts have been demonstrated to possess high selectivity, but their precious price limits their future large-scale applications. Thus, simultaneously achieving high selectivity and reasonable price is of great importance for the development of Au-based catalysts. Here, we report Ag@Au core-shell nanowires as electrocatalyst for CO2 reduction, in which a nanometer-thick Au film is uniformly deposited on the core Ag nanowire. Importantly, the Ag@Au catalyst with a relative low Au content can drive CO generation with nearly 100 % Faraday efficiency in 0.1 m KCl electrolyte at an overpotential of ca. -1.0 V. This high selectivity of CO2 reduction could be attributed to a suitable adsorption strength for the key intermediate on Au film together with the synergistic effects between the Au shell and Ag core and the strong interaction between CO2 and Cl- ions in the electrolyte, which may further pave the way for the development of high-efficiency electrocatalysts for CO2 reduction.

中文翻译：

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Ag @ Au核壳纳米线可实现近100％的CO2到CO的电还原。

将二氧化碳（CO2）电化学还原为CO被认为是利用温室气体CO2的有效方法，因为该CO产品可以通过Fisher-Tropsch工艺进一步转化为高附加值的化学品。在用于CO2到CO还原的所有电催化剂中，金基催化剂已被证明具有很高的选择性，但其昂贵的价格限制了它们未来的大规模应用。因此，同时获得高选择性和合理的价格对于开发Au基催化剂非常重要。在这里，我们报道了Ag @ Au核壳纳米线作为还原CO2的电催化剂，其中纳米厚度的Au膜均匀地沉积在核心Ag纳米线上。重要的，Au含量相对较低的Ag @ Au催化剂可在0.1 m KCl的电解液中以约100的超电势驱动CO生成，并具有近100％的法拉第效率。-1.0V。CO2还原的高选择性归因于关键中间体在Au膜上的合适吸附强度，以及Au壳层与Ag核之间的协同作用以及电解质中CO2与Cl-离子之间的强相互作用，这可能会进一步为开发用于还原CO2的高效电催化剂铺平道路。