Pore-Edge Tailoring of Single-Atom Iron–Nitrogen Sites on Graphene for Enhanced CO2 Reduction

作者：Fuping Pan, Boyang Li, Erik Sarnello, Yuhuan Fei, Xuhui Feng, Yang Gang, Xianmei Xiang, Lingzhe Fang, Tao Li, Yun Hang Hu, Guofeng Wang, Ying Li · 发表于：ACS Catalysis · 年份：2020 · DOI：10.1021/acscatal.0c02499 · 被引用次数：203 · 研究领域：CO2 Reduction Techniques and Catalysts、Electrocatalysts for Energy Conversion、Ionic liquids properties and applications

Hosting atomically dispersed nitrogen-coordinated iron sites (Fe–N 4 ) on graphene offers unique opportunities for driving electrochemical CO 2 reduction reaction (CO 2 RR) to CO. However, the strong adsorption of *CO on the Fe–N 4 site embedded in intact graphene limits current density due to slow CO desorption process. Herein, we report how the manipulation of pore edges on graphene alters the local electronic structure of isolated Fe–N 4 sites and improves their intrinsic reactivity for prompting CO generation. We demonstrate that constructing holes on graphene basal plane to support Fe–N 4 can significantly enhance its CO 2 RR compared to the pore-deficient graphene-supported counterpart, exhibiting a CO Faradaic efficiency of 94% and a turnover frequency of 1630 h –1 at 0.58 V vs RHE. Mechanistic studies reveal that the incorporation of pore edges results in the downshifting of the d-band center of Fe sites, which weakens the strength of the Fe–C bond when the *CO intermediate adsorbs on edge-hosted Fe–N 4, thus boosting the CO desorption and evolution rates. These findings suggest that engineering local support structure renders a way to design high-performance single-atom catalysts.