Zeolitic imidazole framework-derived FeN5-doped carbon as superior CO2 electrocatalysts

Abstract

Electrochemical CO2 conversion offers a sustainable approach to alleviate the energy crisis but remains a long-standing challenge. Herein, atomically dispersed FeN5 sites anchored on N-doped carbon matrix templated by zeoliticimidazoleframework-8 (ZIF-8) are facilely synthesized for efficient catalyzing CO2 reduction. The FeN5 single-atom catalyst (Fe-SA/ZIF) presents the Faradaic efficiency of 98% at −0.7 V vs. RHE and over 95% in a wide potential range from −0.4 to −1.0 V vs. RHE, surpassing most of the reported single-atom catalysts for CO2RR. Further density functional theory (DFT) calculations reveal that the outstanding activity of FeN5 sites mainly originates from the lowered d-band center modulated by the out-of-plane coordinated pyridinic N, which reduces the CO adsorption energy from −1.71 to −1.49 eV compared to FeN4 moieties. Thus, the synergistic effect between FeN4 sites and the coordinated pyridine offers new insight in designing outstanding electrocatalysts for multiple applications.