Authors: Xin‐Yu Wu, Jian‐Feng Lu, Shan Zou, Jian Zhao, Sheng‐Li Hou, Zi‐Hao Zhu, Hui Xu, Sui‐Jun Liu, He‐Rui Wen
Published: 2025-06-02
Source: Full article
AbstractThe electrochemical CO2 reduction reaction (CO2RR) to formic acid presents a promising approach for CO2 utilization. In this work, a new Bi‐MOF (JXUST‐302) with seven‐coordinated Bi nodes is constructed as the electrocatalyst for CO2RR. JXUST‐302 exhibits a high Faraday efficiency for HCOO– (FEHCOO–) of 95.5% with a partial current density (jHCOO–) of –146.2 mA cm−2, and FEHCOO– maintains more than 90% at a wide potential range of 700 mV. Furthermore, the FEHCOOH reaches a high value of 98.8% with jHCOOH of 92.9 mA cm−2 in the membrane electrode assembly cell with solid‐state electrolyte over 12 h for pure formic acid production. Controlled experiments suggest that the low coordination number of JXUST‐302 results in more than a three‐fold improvement in jHCOO– compared to another high coordination number of Bi‐MOF with similar structure and porosity. Mechanistic studies reveal that the lower coordination number confers an optimized electronic structure of the Bi site to lower the p‐band center while allowing the *OCHO intermediates to bind in a bridging mode, thus facilitating the reduction of CO2 to HCOOH. This work represents an important example of regulating the coordination of catalysis to enhance the CO2RR performance.