98. Electrosynthesis of Ethylene Glycol from Methanol via Oxidative C–C Coupling

Xi Wang, Chunyu Zhang, Leshu Zhan, Yuanbo Liu, An-Zhen Li, Bo-Jun Yuan, Xiang Liu, Haohong Duan*
J. Am. Chem. Soc. 2026.
DOI: 10.1021/jacs.6c03536

Abstract
Ethylene glycol (EG) is a commodity chemical, but its industrial production heavily relies on fossil-based feedstocks (that are, oil-based ethylene and coal-based syngas) and faces high carbon footprint. Herein, we report one-step electrosynthesis of EG from an important C1 platform molecule─methanol (MeOH), via oxidative C–C coupling at the anode. Over a boron-doped diamond (BDD) electrode, EG was produced with a Faradaic efficiency of 34.3% and a selectivity of 48.7% at a current density of 100 mA cm^–2, delivering a productivity of 639 μmol cm^–2 h^–1. Mechanistic studies revealed that the reaction proceeded via a radical-mediated pathway, wherein H₂O was first oxidized to the hydroxyl radical (^•OH) on the BDD electrode, which mediated C–H bond activation of MeOH to deliver the ^•CH₂OH intermediate, following C–C coupling to generate EG. To enhance EG selectivity, a paired-electrolysis strategy was designed that couples MeOH-to-EG at the anode and reduction of the byproduct formaldehyde to MeOH at the cathode. In a membrane-free flow cell, EG selectivity was increased from 48.7% to 72.1% with cycling stability over 80 h. This work demonstrates the opportunity to synthesize carbon-chain-propagated chemicals from basic C1 feedstock via radical-type C–C coupling by electrocatalysis.