Under the complex external reaction conditions, uncovering the true structural evolution of the catalyst is of profound significance for the establishment of relevant structure–activity relationships and the rational design of electrocatalysts. Here, the surface reconstruction of the catalyst was characterized by ex-situ methods and in-situ Raman spectroscopy in CO₂ electroreduction. The final results showed that the Bi₂O₃ nanoparticles were transformed into Bi/Bi₂O₃ two-dimensional thin-layer nanosheets (NSs). It is considered to be the active phase in the electrocatalytic process. The Bi/Bi₂O₃ NSs showed good catalytic performance with a Faraday efficiency (FE) of 94.8% for formate and a current density of 26 mA cm⁻² at −1.01 V. While the catalyst maintained a 90% FE in a wide potential range (−0.91 V to −1.21 V) and long-term stability (24 h). Theoretical calculations support the theory that the excellent performance originates from the enhanced bonding state of surface Bi-Bi, which stabilized the adsorption of the key intermediate OCHO* and thus promoted the production of formate.

中文翻译：

---

用于 CO2 电还原的 Bi2O3 纳米粒子催化剂的原位结构演变

在复杂的外部反应条件下，揭示催化剂的真实结构演化对于相关结构-活性关系的建立和电催化剂的合理设计具有深远的意义。在这里，催化剂的表面重建的特点是迁地方法和就地_{CO 2}电还原中的拉曼光谱。最终结果表明，Bi ₂ O ₃纳米粒子转变为Bi/Bi ₂ O ₃二维薄层纳米片(NSs)。它被认为是电催化过程中的活性相。Bi/Bi ₂ O ₃ NSs 表现出良好的催化性能，甲酸盐的法拉第效率 (FE) 为 94.8%，电流密度为 26 mA cm ^-2在-1.01 V。虽然催化剂在宽电位范围（-0.91 V 至-1.21 V）和长期稳定性（24 小时）内保持 90% FE。理论计算支持这样的理论，即优异的性能源于表面Bi-Bi增强的键合状态，稳定了关键中间体OCHO*的吸附，从而促进了甲酸盐的产生。