Efficient Electro-Oxidation of Ethylene to 2-Chloroethanol on SnO₂ Through Dual-Adsorbate Pathway

Electrified 2-chloroethanol synthesis serves as a promising alternative to conventional ethylene oxidation with corrosive hypochlorous acid (HClO) and offers the opportunity for sustainable pharmaceutical production. However, the instability of locally generated HClO and the competing water oxidation largely limit the efficiency of this electrochemical process. Here we report a new reaction pathway involved in the ethylene oxidation toward 2-chloroethanol, featuring co-adsorbed chloride (*Cl) and hydroxide (*OH) species on a tin dioxide (SnO₂) anode. This dual-adsorbate pathway favors the efficient ethylene oxidation, giving rise to a large current density of 100 mA cm^-2 for at least 50 h and a high Faradaic efficiency (FE) of up to 82% for the 2-chloroethanol product. This work opens an avenue for electrifying the synthesis of important organic molecules via simultaneously modulating the adsorption of multiple active intermediates.