Li Zhengyuan, Wang Peng, Han Guanqun, Yang Shize, Roy Soumyabrata, Xiang Shuting, Jimenez Juan D, Kondapalli Vamsi Krishna Reddy, Lyu Xiang, Li Jianlin, Serov Alexey, Li Ruizhi, Shanov Vesselin, Senanayake Sanjaya D, Frenkel Anatoly I, Ajayan Pulickel M, Sun Yujie, Senftle Thomas P, Wu Jingjie
Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, USA.
Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA.
Nat Commun. 2025 May 25;16(1):4850. doi: 10.1038/s41467-025-60008-9.
Current catalysts face challenges with low formate selectivity at high current densities during the CO electroreduction. Here, we showcase a versatile strategy to enhance the formate production on p-block metal-based catalysts by incorporating noble metal atoms on their surface, refining oxygen affinity, and tuning adsorption of the critical oxygen-bound *OCHO intermediate. The formate yield is observed to afford a volcano-like dependence on the *OCHO binding strength across a series of modified catalysts. The rhodium-dispersed indium oxide (Rh/InO) catalyst exhibits impressive performances, achieving Faradaic efficiencies (FEs) of formate exceeding 90% across a broad current density range of 0.20 to 1.21 A cm. In situ Raman spectroscopy and theoretical calculations reveal that the oxophilic Rh site facilitates *OCHO formation by optimizing its adsorption energy, placing Rh/InO near the volcano-shaped apex. A bipolar electrosynthesis system, coupling the CO reduction at the cathode with the formaldehyde oxidative dehydrogenation at the anode, further boosts the FE of formate to nearly 190% with pure hydrogen generation under an ampere-level current density and a low cell voltage of 2.5 V in a membrane electrode assembly cell.
在CO电还原过程中，当前的催化剂在高电流密度下存在甲酸盐选择性低的问题。在此，我们展示了一种通用策略，通过在p族金属基催化剂表面引入贵金属原子、改善氧亲和力以及调节关键的氧结合OCHO中间体的吸附，来提高甲酸盐的生成量。观察到在一系列改性催化剂中，甲酸盐产率对OCHO结合强度呈现出类似火山的依赖性。铑分散的氧化铟（Rh/InO）催化剂表现出令人印象深刻的性能，在0.20至1.21 A cm的宽电流密度范围内，甲酸盐的法拉第效率（FE）超过90%。原位拉曼光谱和理论计算表明，亲氧的Rh位点通过优化其吸附能促进*OCHO的形成，使Rh/InO接近火山形状的顶点。一种双极电合成系统，将阴极的CO还原与阳极的甲醛氧化脱氢相结合，在膜电极组装电池中，在安培级电流密度和2.5 V的低电池电压下，进一步将甲酸盐的FE提高到近190%，同时产生纯氢。
