广西大学何会兵课题组取得一项新突破。他们通过大气诱导可调氧空位稳定铈中的单原子铜，用于稳健的电催化CO₂还原为CH₄。相关论文于2024年9月23日发表在《德国应用化学》杂志上。

据了解，电化学二氧化碳还原(ECO₂RR)显示出创造高价值碳基化学品的巨大潜力，但在原子水平上设计先进的催化剂仍然具有挑战性。ECO₂RR的性能很大程度上取决于催化剂的微电子结构，而微电子结构可以通过表面缺陷工程进行有效调节。

课题组人员提供了一种气氛辅助低温煅烧策略，以制备一系列具有不同氧空位浓度的单原子Cu/ceria催化剂，用于稳健的电解将CO₂还原为甲烷。在H₂环境下制备的Cu/ceria催化剂(Cu/ceria-H₂)，在试验尺度电流密度为150 mA cm^-2的流动池中，甲烷法拉第效率(FECH₄)为70.03%，转化率(TOFCH₄)为9946.7 h^-1。详细研究表明，Cu/ceria-H₂中的富氧空位有利于Cu⁺活性中心稳定的表面微电子结构的调控。

此外，密度泛函理论计算和工作ATR-SEIRAS表明，Cu/ceria-H₂可以显著增强CO₂的活化，促进关键中间体*COOH和*CO的吸附，最终实现CH₄的高选择性生成。本研究为通过反应气氛控制表面微观结构，来设计有效的CO₂转化为CH₄的电催化剂提供了深入的见解。

附：英文原文

Title: Atmosphere Induces Tunable Oxygen Vacancies to Stabilize Single-Atom Copper in Ceria for Robust Electrocatalytic CO2 Reduction to CH4

Author: Fang Huang, Xiangyu Chen, Huanhuan Sun, Qingduo Zeng, Junjie Ma, Dong Wei, Jinliang Zhu, Zhengjun Chen, Taoyuan Liang, Xucai Yin, Xijun Liu, Jing Xu, Huibing He

Issue&Volume: 2024-09-23

Abstract: Electrochemical carbon dioxide reduction (ECO2RR) shows great potential to create high-value carbon-based chemicals, while designing advanced catalysts at the atomic level remains challenging. The ECO2RR performance is largely dependent on the catalyst microelectronic structure that can be effectively modulated through surface defect engineering. Here, we provide an atmosphere-assisted low-temperature calcination strategy to prepare a series of single-atomic Cu/ceria catalysts with varied oxygen vacancy concentrations for robust electrolytic reduction of CO2 to methane. The obtained Cu/ceria catalyst under H2 environment (Cu/ceria-H2) exhibits a methane Faraday efficiency (FECH4) of 70.03% with a turnover frequency (TOFCH4) of 9946.7 h1 at an industrial-scale current density of 150 mA cm2 in a flow cell. Detailed studies indicate the copious oxygen vacancies in the Cu/ceria-H2 are conducive to regulating the surface microelectronic structure with stabilized Cu+ active center. Furthermore, density functional theory calculations and operando ATR-SEIRAS demonstrate that the Cu/ceria-H2 can markedly enhance the activation of CO2, facilitate the adsorption of pivotal intermediates *COOH and *CO, thus ultimately enabling the high selectivity for CH4 production. This study presents deep insights into designing effective electrocatalysts for CO2 to CH4 conversion by controlling the surface microstructure via the reaction atmosphere.

DOI: 10.1002/anie.202415642

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202415642