摘要
Renewable electricity-driven CO evolu-tion from CO_(2)offers a promising route for sustainable chemical production.Single-atom alloy(SAA)catalysts are emerging as promising candidates for electrochemical CO_(2)reduction.Howev-er,the dynamic nature of SAAs within their local microenvironment often com-plicates our understanding of the under-lying mechanisms that contribute to their enhanced performance.In this study,we introduce a single-atom Co-modified Au nanoparticle catalyst(Co_(1)O_(x)@Au)for the electrocatalytic re-duction of CO_(2)to CO.Using operando X-ray absorption spectroscopy(XAS),we observe the dynamic transformation of Co_(1)O_(x)@Au into a low-valence Co_(1)Au SAA,driven by the applied voltages.This behavior strengthens the atomic interaction between Au and Co,thus ensuring a reinforced adsorption of the crucial^(*)COOH intermediate,which is corroborated by operan-do synchrotron-radiation Fourier transform infrared spectroscopy(SR-FTIR).Furthermore,the strengthened Au-Co interaction facilitates the subsequent desorption of the^(*)CO interme-diate,allowing for efficient CO formation and release.These insights highlight the self-opti-mization behavior of SAAs towards improving CO_(2)reduction selectivity.
可再生电力驱动的二氧化碳(CO_(2))至一氧化碳(CO)转化为可持续的化学品生产提供了一条有前景的途径.在这一领域,单原子合金催化剂正日益凸显其作为电化学CO_(2)还原反应高效催化剂的巨大潜力.然而,单原子合金在其局部微环境中的复杂动态行为使得理解其性能提升的潜在机制变得困难.本文介绍了一种单原子钴改性的金纳米粒子催化剂(Co_(1)O_(x)@Au)用于CO_(2)电催化还原为CO,通过原位X射线吸收光谱观察到Co_(1)O_(x)@Au在施加电压的驱动下转化为低价的Co_(1)Au-单原子合金,这种现象增强了Au和Co之间的原子相互作用.原位同步辐射傅里叶变换红外光谱进一步证实,这种加强的Au-Co相互作用有利于关键中间体^(*)COOH的吸附,同时有助于后续CO中间体的解吸,从而有效地生成和释放CO.结果表明,单原子合金催化剂的自优化行为可以有效提高二氧化碳还原反应的选择性.
基金
supported by the National Natural Science Foundation of China(Nos.12105287 and 12205304)。
