Selective Electrochemical Reduction of CO₂ to Ethanol on a Heteroatom-Coordinated Dual-Atom Catalyst of Fe/Cu-NC

Abstract

Rising CO2 emissions, particularly from industrial sectors, are driving climate change and causing severe environmental and energy crises that demand immediate action. The electrochemical CO2 reduction reaction (eCO2RR) provides a sustainable approach by converting waste CO2 into value-added products. However, achieving a high selectivity for multicarbon products in the eCO2RR requires advanced catalysts with large surface areas, accessible active sites, and strong synergistic interactions. Here, we introduce a dual-atom Fe/Cu-NC catalyst synthesized through a metal–organic framework (MOF)-derived method where Fe and Cu atoms are uniformly dispersed on a porous nitrogen-doped carbon matrix, forming dual heteroactive Fe–N4 and Cu–N3 sites. The strategic combination of these active sites significantly enhances catalytic performance, achieving a 67.4% Faradaic efficiency (FE) for ethanol at −0.8 V vs RHE in CO2-saturated 0.5 M KHCO3. In situ spectroscopic analysis confirms the formation of major *CO and *CHO intermediates during CO2 electrolysis on the Fe/Cu-NC electrode, which are crucial for C–C coupling and ethanol production. DFT studies reveal that Fe–N4 and Cu–N3 sites synergistically lower the *CO intermediate energy barriers. Fe–N4 enriches the local CO concentration, which migrates to Cu–N3, enhancing ethanol production. This highlights MOF-derived dual-atom catalysts as a promising strategy for efficient CO2 conversion into ecofriendly products with zero emissions.