Niu Wenzhe, Chen Zheng, Guo Wen, Mao Wei, Liu Yi, Guo Yunna, Chen Jingzhao, Huang Rui, Kang Lin, Ma Yiwen, Yan Qisheng, Ye Jinyu, Cui Chunyu, Zhang Liqiang, Wang Peng, Xu Xin, Zhang Bo
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China.
Department of Chemistry, MOE Key Laboratory of Computational Physical Sciences, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China.
Nat Commun. 2023 Aug 12;14(1):4882. doi: 10.1038/s41467-023-40689-w.
Electrochemical carbon monoxide (CO) reduction to high-energy-density fuels provides a potential way for chemical production and intermittent energy storage. As a valuable C species, n-propanol still suffers from a relatively low Faradaic efficiency (FE), sluggish conversion rate and poor stability. Herein, we introduce an "atomic size misfit" strategy to modulate active sites, and report a facile synthesis of a Pb-doped Cu catalyst with numerous atomic Pb-concentrated grain boundaries. Operando spectroscopy studies demonstrate that these Pb-rich Cu-grain boundary sites exhibit stable low coordination and can achieve a stronger CO adsorption for a higher surface CO coverage. Using this Pb-Cu catalyst, we achieve a CO-to-n-propanol FE (FE) of 47 ± 3% and a half-cell energy conversion efficiency (EE) of 25% in a flow cell. When applied in a membrane electrode assembly (MEA) device, a stable FE above 30% and the corresponding full-cell EE of over 16% are maintained for over 100 h with the n-propanol partial current above 300 mA (5 cm electrode). Furthermore, operando X-ray absorption spectroscopy and theoretical studies reveal that the structurally-flexible Pb-Cu surface can adaptively stabilize the key intermediates, which strengthens the *CO binding while maintaining the C-C coupling ability, thus promoting the CO-to-n-propanol conversion.
将电化学一氧化碳（CO）还原为高能量密度燃料为化学生产和间歇性储能提供了一条潜在途径。作为一种有价值的碳物种，正丙醇的法拉第效率（FE）仍然相对较低，转化率缓慢且稳定性较差。在此，我们引入一种“原子尺寸失配”策略来调节活性位点，并报告了一种简便合成具有大量原子级铅富集晶界的铅掺杂铜催化剂的方法。原位光谱研究表明，这些富含铅的铜晶界位点表现出稳定的低配位状态，并且能够实现更强的CO吸附，从而获得更高的表面CO覆盖率。使用这种铅 - 铜催化剂，我们在流动池中实现了47±3%的CO到正丙醇的法拉第效率（FE）以及25%的半电池能量转换效率（EE）。当应用于膜电极组件（MEA）装置时，在正丙醇分电流高于300 mA（5 cm电极）的情况下，超过100小时内保持稳定的FE高于30%以及相应的全电池EE超过16%。此外，原位X射线吸收光谱和理论研究表明，结构灵活的铅 - 铜表面可以自适应地稳定关键中间体，这增强了*CO结合力，同时保持了C - C偶联能力，从而促进了CO到正丙醇的转化。
