Electrochemical CO2 reduction reaction (CO2RR) offers a sustainable strategy for producing fuels and chemicals. However, it suffers from sluggish CO2 activation and slow water dissociation. In this work, we construct a (P‐O)δ− modified In catalyst that exhibits high activity and selectivity in electrochemical CO2 reduction to formate. A combination of in‐situ characterizations and kinetic analyses indicate that (P‐O)δ− has a strong interaction with K+(H2O)n, which effectively accelerates water dissociation to provide protons. In‐situ attenuated total reflectance surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) measurements together with density functional theory (DFT) calculations disclose that (P‐O)δ− modification leads to a higher valence state of In active site, thus promoting CO2 activation and HCOO* formation, while inhibiting competitive hydrogen evolution reaction (HER). As a result, the (P‐O)δ− modified oxide‐derived In catalyst exhibits excellent formate selectivity across a broad potential window with a formate Faradaic efficiency as high as 92.1% at a partial current density of ~200 mA cm−2 and a cathodic potential of ‐1.2 V vs. RHE in an alkaline electrolyte.

中文翻译：

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磷酸盐改性增强电化学 CO2 还原成甲酸盐：水活化和活性位点调节

电化学二氧化碳还原反应 (CO2RR) 为生产燃料和化学品提供了可持续的策略。然而，它的二氧化碳活化缓慢且水解离缓慢。在这项工作中，我们构建了一种 (P-O)δ− 修饰的 In 催化剂，该催化剂在电化学 CO2 还原成甲酸盐方面表现出高活性和选择性。原位表征和动力学分析相结合表明，(P-O)δ− 与 K+(H2O)n 具有很强的相互作用，可有效加速水解离以提供质子。原位衰减全反射表面增强红外吸收光谱（ATR-SEIRAS）测量与密度泛函理论（DFT）计算一起揭示了（P-O）δ-修饰导致In活性位点的价态更高，从而促进CO2 活化和 HCOO* 形成，同时抑制竞争性析氢反应 (HER)。因此，(P-O)δ-改性氧化物衍生In催化剂在较宽的电位窗口内表现出优异的甲酸盐选择性，在~200 mA cm−2的部分电流密度下，甲酸盐法拉第效率高达92.1%碱性电解质中相对于 RHE 的阴极电位为 ‐1.2 V。