Covalently Modified Electrode with Bismuth Nanoparticles Encapsulated in Ultrathin Porous Organic Polymer Linked by Amine Bonding for Efficient CO 2 Electroreduction

作者：Li Cui, Yan Wang, Changjiang Wang, Qichao Wu, Xuyu Lv, Shuxian Xie, Lichun Kong, Jiu‐Ju Feng, Zhengquan Li, Ai‐Jun Wang, Jinwei Kang, Yang Fa · 发表于：ACS Applied Materials & Interfaces · 年份：2025 · DOI：10.1021/acsami.5c01473 · 被引用次数：6 · 研究领域：CO2 Reduction Techniques and Catalysts、Covalent Organic Framework Applications、Ionic liquids properties and applications

Bismuth-based materials in electrocatalytic CO 2 reduction (CO 2 RR) usually face the problem of high overpotential. We first show a covalently modified electrode with Bi nanoparticles encapsulated in ultrathin porous organic polymer nanosheets (POPs) with amine linkages to effectively reduce the overpotential for the CO 2 -to-formate conversion, which exhibits a high formate Faradaic efficiency (FE HCOO– ) of 98.5% and a partial current density up to 148.7 mA cm –2 at −0.85 V in comparison with that of a bare bismuth electrode with a FE HCOO– of 85% at −1.15 V (versus a reversible hydrogen electrode). Different from the reaction mechanism with *CO 2 •– radicals as the intermediate over bare Bi sites, in situ spectroscopic studies and density functional theory calculations reveal that the abundant amine linkages in the POPs backbone provide chemisorption sites to interact with enriched CO 2 molecules to form carbamates (*[–NCOO–]) intermediates with a low reaction barrier of 0.064 eV, which significantly reduces the free energy for the conversion process of CO 2 to formate. Moreover, the modified amine linkages promote water dissociation and the subsequent protonation reaction on the Bi surface with a reduced dissociation energy of −0.31 eV than that on the bare Bi surface of 0.11 eV. This work not only delivers a new mechanism for the CO 2 -to-formate conversion but also offers a clean platform to investigate the influence of covalently modification.