Yu Xiaohan, Xu Yuting, Li Le, Zhang Mingzhe, Qin Wenhao, Che Fanglin, Zhong Miao
College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, the Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, 210093, China.
Department of Chemical Engineering, University of Massachusetts Lowell, Lowell, MA, 01854, USA.
Nat Commun. 2024 Feb 24;15(1):1711. doi: 10.1038/s41467-024-45988-4.
Acidic CO electroreduction (COR) using renewable electricity holds promise for high-efficiency generation of storable liquid chemicals with up to 100% CO utilization. However, the strong parasitic hydrogen evolution reaction (HER) limits its selectivity and energy efficiency (EE), especially at ampere-level current densities. Here we present that enhancing COR intermediate coverage on catalysts promotes COR and concurrently suppresses HER. We identified and engineered robust CuSn catalysts with strong OCHO affinity and weak H binding, achieving 91% Faradaic efficiency (FE) for formic acid (FA) production at 1.2 A cm and pH 1. Notably, the single-pass carbon efficiency reaches a new benchmark of 77.4% at 0.5 A cm over 300 hours. In situ electrochemical Fourier-transform infrared spectroscopy revealed CuSn enhances OCHO coverage ~2.8× compared to Sn at pH 1. Using a cation-free, solid-state-electrolyte-based membrane-electrode-assembly, we produce 0.36 M pure FA at 88% FE over 130 hours with a marked full-cell EE of 37%.
利用可再生电力进行酸性CO电还原（COR）有望高效生成可储存的液体化学品，且CO利用率高达100%。然而，强烈的析氢副反应（HER）限制了其选择性和能量效率（EE），尤其是在安培级电流密度下。在此，我们提出增强催化剂上COR中间体的覆盖率可促进COR，同时抑制HER。我们鉴定并设计了具有强OCHO亲和力和弱H结合能力的稳健CuSn催化剂，在1.2 A cm和pH值为1的条件下，甲酸（FA）生产的法拉第效率（FE）达到91%。值得注意的是，在0.5 A cm的电流密度下，单通道碳效率在300小时内达到了77.4%的新基准。原位电化学傅里叶变换红外光谱显示，在pH值为1时，与Sn相比，CuSn使OCHO覆盖率提高了约2.8倍。使用基于无阳离子固态电解质的膜电极组件，我们在130小时内以88%的FE生产了0.36 M的纯FA，全电池EE显著达到37%。
