Boosting electrocatalytic CO 2 -to-ethanol production via asymmetric C-C coupling.

Electroreduction of carbon dioxide (CO 2 ) into multicarbon products provides possibility of large-scale chemicals production and is therefore of significant research and commercial interest. However, the production efficiency for ethanol (EtOH), a significant chemical feedstock, is impractically low because of limited selectivity, especially under high current operation. Here we report a new silver-modified copper-oxide catalyst (dCu 2 O/Ag 2.3% ) that exhibits a significant Faradaic efficiency of 40.8% and energy efficiency of 22.3% for boosted EtOH production. Importantly, it achieves CO 2 -to-ethanol conversion under high current operation with partial current density of 326.4 mA cm -2 at -0.87 V vs reversible hydrogen electrode to rank highly significantly amongst reported Cu-based catalysts. Based on in situ spectra studies we show that significantly boosted production results from tailored introduction of Ag to optimize the coordinated number and oxide state of surface Cu sites, in which the * CO adsorption is steered as both atop and bridge configuration to trigger asymmetric C-C coupling for stablization of EtOH intermediates.