CO₂ electroreduction is favorable in neutral or alkaline aqueous solutions, where H₂O serves as the proton source, suffering from sluggish dynamics. Herein, we synthesize a series of SnO₂-CeO₂ with different oxygen vacancy (O_v) concentration, regulating the H₂O dissociation, to synchronize with the CO₂ reduction. The optimal SnO₂-CeO₂ catalyst, with a moderate O_v concentration, exhibits a formate Faradic efficiency of nearly 93 % and maintains for more than 46 h at a current density of 100 mA/cm². The catalyst with lower O_v concentration results in weak H₂O dissociation, thus enhancing the energy barrier of *OCHO generation, while higher O_v concentration leads to excessive proton, exacerbating the hydrogen evolution reaction (HER), as supported by DFT calculation and in situ attenuated total reflection-Fourier transform infrared spectra (ATR-FTIR). This study underscores the significance of O_v concentration in determining the ability of water dissociation over supported electrocatalysts, providing valuable insights for the development of more efficient electrocatalyst.

中文翻译：

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调整氧空位以实现对 CeO2 负载的 SnO 2 的高效 CO2 电还原


CO₂ 电还原在中性或碱性水溶液中是有利的，其中 H₂O 作为质子源，动力学缓慢。在此，我们合成了一系列具有不同氧空位 （O_v） 浓度的 SnO_{2-CeO 2}，调节 H₂O 解离，以同步 CO₂ 还原。最佳的 SnO_{2-CeO 2} 催化剂，具有中等 O_v 浓度，表现出近 93 % 的甲酸盐法拉第效率，并在 100 mA/cm² 的电流密度下保持 46 小时以上。O_v 浓度较低的催化剂导致弱 H₂O 解离，从而增强 *OCHO 生成的能量势垒，而较高的 O_v 浓度导致质子过多，加剧析氢反应 （HER），正如 DFT 计算和原位衰减全反射傅里叶变换红外光谱 （ATR-FTIR） 所支持的那样。本研究强调了 O_v 浓度在确定负载型电催化剂上水解离能力的重要性，为开发更高效的电催化剂提供了有价值的见解。