Fluorine Doping-Assisted Reconstruction of Isolated Cu Sites for CO₂ Electroreduction Toward Multicarbon Products

The electrocatalytic synthesis of multicarbon compounds from CO₂ is a promising method for storing renewable electricity and addressing global CO₂ issues. Single-atom catalysts are promising candidates for CO₂ reduction, but producing high-value multicarbon (C₂₊) products using a single-atom structure remains a significant challenge. In this study, a fluorine doping strategy is proposed to facilitate the reconstruction of isolated Cu atoms, promoting multicarbon generation. The in situ formed Cu nanocrystals contain a substantial amount of stable Cu⁺ species, demonstrating remarkable activity for CO₂−to-multicarbon conversion. Notably, they achieve the highest Cu utilization, with a C₂₊ partial current density of −2.01 A mg_{per Cu}⁻¹and a C₂₊ formation rate of 7.03 mmol h⁻¹ mg_{per Cu}⁻¹at ≈−1 V versus RHE. In situ Raman spectroscopy and density functional theory calculations confirm the crucial role of fluorine atoms in structural evolution and electrolysis.