Bismuth (Bi)-based materials show the great potential for electrochemical reduction of CO₂ to formate due to their low toxicity and accelerating *OCHO production, but there are many challenges in their activity and practicality. Here we report the preparation of CeO_x-Bi₂O₂CO₃ nanosheet catalysts with abundant oxygen vacancies by introducing the more economical rare earth element cerium (Ce), which exhibits better performance in the conversion of CO₂RR to formate. CeO_x-Bi₂O₂CO₃ could maintain high activity within a wide potential window to obtain more than 90% formate selectivity and stability for 17 h in H-type cell and improve the Faradaic efficiency of formate in the flow cell. In situ IR and Density functional theory (DFT) calculations indicate a significant synergistic effect on CO₂RR between CeO_x and Bi₂O₂CO₃, because CeO_x can modulate the electron cloud density of Bi and improve the adsorption of key intermediates. Also, a large number of unsaturated sites could lower the energy barrier of *OCHO production, inhibit H₂ production, and accelerate the electron transfer to generate formate. This work explores the reaction pathway of formate production from Ce-doped Bi-based catalysts and provides new insights into the design of oxygen vacancy-rich Bi-based catalysts for efficient CO₂RR.

铋(Bi)基材料由于其低毒性和加速*OCHO生产而显示出电化学还原CO _{2生成甲酸盐的巨大潜力，但其活性和实用性仍存在许多挑战。}在此，我们报道了通过引入更经济的稀土元素铈（Ce）制备了具有丰富氧空位的CeO _x -Bi ₂ O ₂ CO _{3纳米片催化剂，该催化剂在CO 2} RR转化为甲酸盐方面表现出更好的性能。CeO _x -Bi ₂ O ₂ CO ₃可以在较宽的电位窗口内保持高活性，在 H 型池中获得超过 90% 的甲酸选择性和 17 小时的稳定性，并提高流通池中甲酸的法拉第效率。原位红外和密度泛函理论（DFT）计算表明CeO _x和Bi ₂ O ₂ CO _{3对CO 2} RR具有显着的协同效应，因为CeO _x可以调节Bi的电子云密度并提高关键中间体的吸附。此外，大量的不饱和位点可以降低*OCHO产生的能垒，抑制H ₂生产，并加速电子转移生成甲酸盐。_{这项工作探索了Ce掺杂的Bi基催化剂生产甲酸盐的反应途径，并为高效CO 2} RR的富氧空位Bi基催化剂的设计提供了新的见解。