Main-Group Metal Single-Atomic Regulators in Dual-Metal Catalysts for Enhanced Electrochemical CO2 Reduction

Authors：Hu, Chenghong; Wang, Yajing; Chen, Jianmin; Wang, Hao-Fan; Shen, Kui; Tang, Kewen; Chen, Liyu^*; Li, Yingwei^*

Source：Small, 2022, 18(22): 2201391.

DOI：10.1002/smll.202201391

• CO
• (2) reduction
• dual-metal sites
• electrocatalysis
• electronic effect
• single-atom catalysts

Single-atom sites can not only act as active centers, but also serve as promising catalyst regulators and/or promoters. However, in many complex reaction systems such as electrochemical CO2 reduction reaction (CO2RR), the introduction of single-atom regulators may inevitably induce the competitive hydrogen evolution reaction (HER) and thus reduce the selectivity. Here, the authors demonstrate that introducing HER-inert main-group metal single atoms adjacent to transition-metal single atoms can modify their electronic structure to enhance the CO2RR to CO without inducing the HER side reaction. Dual-metal Cu and In single-site atoms anchored on mesoporous nitrogen-doped carbon (denoted as Cu-In-NC) are prepared by the pyrolysis of a multimetallic metal-organic framework. Cu-In-NC shows a high faradic efficiency of 96% toward CO formation at -0.7 V versus reversible hydrogen electrode, superior to that of its monometallic single-atom counterparts. Density functional theory studies reveal that the HER-inert In sites can activate the adjacent Cu sites through electronic modifications, strengthening the binding of *COOH intermediate and thus boosting the electrochemical reduction of CO2 to CO.