Oxygen vacancy defect engineering is currently an effective strategy to enhance the performance of electrocatalytic CO₂ reduction to CO. In our work, ZnO with oxygen vacancies defects by Ce³⁺ doping were obtained through solvothermal method. The oxygen vacancies defects concentration could be controlled by varying the Ce³⁺ dopant concentration, which initially increased then decreased. And the CO₂ER performance of as-prepared samples is found to be closely dependent with the concentration of oxygen vacancy in the as-prepared Ce_xZn_1-xO. The optimized CO₂ER to CO performances can be obtained from Ce_0.016Zn_0.984O with the highest oxygen vacancy concentrations, which exhibited the highest performance (current density 24 mA cm⁻² and Faradaic efficiency 88% for CO) at -1.0 V versus RHE. Through CO₂ isotherm adsorption curve and CO₂ temperature-programmed desorption (CO₂-TPD) test, it was proved that the high concentration oxygen vacancy of Ce_0.016Zn_0.984O was beneficial to improve the CO₂ adsorption and activation. This study proposes a strategy aimed at obtaining a high-performance catalyst for electrocatalytic CO₂ reduction by adjusting the concentration of oxygen vacancies.

目前，氧空位缺陷工程是提高电催化将CO ₂还原为CO的有效策略。在我们的工作中，通过溶剂热法获得了具有Ce ³⁺掺杂的氧空位缺陷的ZnO 。氧空位缺陷浓度可以通过改变Ce ³⁺掺杂剂的浓度来控制，Ce ³⁺掺杂剂的浓度先升高后降低。并且发现所制备样品的CO ₂ ER性能与所制备Ce _x Zn _1-x O中氧空位的浓度密切相关。可以从Ce _0.016获得最佳的CO ₂ ER对CO性能锌_0.984与RHE相比，在-1.0 V时具有最高氧空位浓度的O表现出最高的性能（CO的电流密度为24 mA cm ^-2，CO的法拉第效率为88％）。通过CO ₂等温线吸附曲线和CO _2程序升温脱附（CO ₂ -TPD）试验，证明Ce _0.016 Zn _0.984 O的高浓度氧空位有利于提高CO _2的吸附和活化。这项研究提出了一种旨在通过调节氧空位浓度来获得用于电催化还原CO ₂的高性能催化剂的策略。