Bismuth‐based electrocatalysts are effective for carbon dioxide (CO2) reduction to formate. However, at room temperature, these materials are only available in solid state, which inevitably suffers from surface deactivation, declining current densities, and Faradaic efficiencies. Here, the formation of a liquid bismuth catalyst on the liquid gallium surface at ambient conditions is shown as its exceptional performance in the electrochemical reduction of CO2 (i.e., CO2RR). By doping a trace amount of bismuth (740 ppm atomic) in gallium liquid metal, a surface enrichment of bismuth by over 400 times (30 at%) in liquid state is obtained without atomic aggregation, achieving 98% Faradic efficiency for CO2 conversion to formate over 80 h. Ab initio molecular simulations and density functional theory calculations reveal that bismuth atoms in the liquid state are the most energetically favorable sites for the CO2RR intermediates, superior to solid Bi‐sites, as well as joint GaBi‐sites. This study opens an avenue for fabricating high‐performing liquid‐state metallic catalysts that cannot be reached by elementary metals under electrocatalytic conditions.

中文翻译：

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用于催化二氧化碳还原的表面富集室温液态铋


铋基电催化剂可有效地将二氧化碳 (CO2) 还原为甲酸盐。然而，在室温下，这些材料只能以固态存在，这不可避免地会遭受表面失活、电流密度下降和法拉第效率的影响。在这里，在环境条件下液态镓表面形成液态铋催化剂，显示出其在 CO2 电化学还原（即 CO2RR）中的卓越性能。通过在液态金属镓中掺杂微量的铋（740 ppm 原子），液态铋的表面富集超过 400 倍（30 at%），且没有原子聚集，实现了 CO2 转化为甲酸盐的 98% 法拉第效率80多个小时。从头算分子模拟和密度泛函理论计算表明，液态铋原子是 CO2RR 中间体最有利的能量位点，优于固体 Bi 位点以及联合 GaBi 位点。这项研究为制造单质金属在电催化条件下无法达到的高性能液态金属催化剂开辟了一条途径。