Industrial electrocatalytic C–C coupling reaction of C1 liquid molecules for efficient ethanol synthesis

Abstract Electrochemical conversion of C1 feedstocks into ethanol (EtOH) offers a promising pathway for achieving efficient carbon cycling and sustainable fuel production. However, conventional electrocatalytic methods suffer from poor mass transfer and lengthy reaction pathways, hindering the concurrent achievement of high current density and selectivity and thus limiting industrial application. Herein, we propose a novel electrocatalytic C–C coupling pathway for EtOH synthesis from liquid formic acid C1 feedstock, achieving high selectivity at high current densities. At 500 mA cm−2, the PdCu electrocatalyst achieves an EtOH Faradaic efficiency of 84.68%, with a formation rate of 1970.1 μmol h−1 cm−2, demonstrating significantly superior overall performance compared to conventional gaseous C1 feedstock electrocatalytic systems. Theoretical and operando spectroscopic studies elucidate that lattice hydrogen at the in situ-formed PdHx sites on PdH0.45Cu/CNT promotes the conversion of electrophilic *HCOO to nucleophilic *C(OH)2, while adjacent Cu promotes asymmetric coupling of *HCOO and *C(OH)2. The PdCu electrocatalyst demonstrates outstanding industrial potential, with 120 h of stable operation at 800 mA cm−2 in an anion exchange membrane (AEM) electrolyzer, validated by technical-economic analysis. Moreover, this mechanism is equally applicable for the efficient conversion of formaldehyde into EtOH. This research proposes a novel pathway for the industrial production of electro-synthesized EtOH.