Optimizing water dissociation through doping fluorine into La2CuO4 to enhance multicarbon generation in CO2 electroreduction
Electrochemical CO2 reduction (eCO2RR) to multicarbon (C2+) products is constrained by the competing hydrogen evolution reaction (HER) and insufficient proton-coupled electron transfer (PCET) kinetics. Here we demonstrate that fluorine doping into La2CuO4 (F-LC) modulates the interfacial hydrogen-bonding network to accelerate H2O dissociation and generate active hydrogen (*H) species, thereby promoting the hydrogenation of adsorbed CO (*CO) to *CHO and facilitating asymmetric *CO–*CHO coupling. The F-LC catalyst achieves a Faradaic efficiency (FE) of 73.0% for C2+ products at −1.2 V vs. RHE, compared to 41.7% for undoped La2CuO4. This enhancement is attributed to the formation of a dense hydrogen-bond network on the F-LC surface, which reorganizes interfacial H2O molecules, enhances proton transfer, and suppresses HER. The results establish a direct correlation between F-induced water dissociation and C–C coupling efficiency, offering a rational design strategy for electrocatalysts capable of steering complex PCET pathways toward high-value multicarbon products.