458210 Electrochemical Reduction of CO2 over Phase-Segregated Cuag Bimetallic Electrodes with Enhanced Oxygenate Selectivity By CO Spillover
Herein we report our investigations of electrochemical CO2 reduction over phase-segregated CuAg bimetallic electrodes, which we have observed to be the only metallic electrocatalysts yet discovered that are more selective for the formation of multi-carbon oxygenates than hydrocarbons. The selectivity of oxygenates relative to hydrocarbons is found to scale with the relative distribution of Cu and Ag facet terminations present at the electrode surface at steady state. The unique selectivity observed over these bimetallic electrodes is explained in terms of CO spillover from the Ag phase to the Cu phase, which results in an enhanced steady state coverage of CO adsorbed to the Cu facet terminations present at the electrode surface. The enhanced coverage of this key reaction intermediate on Cu increases the rate of C-C coupling at the expense of C-H bond formation, resulting in an improved selectivity to multi-carbon oxygenated products at the expense of hydrogen and hydrocarbons.
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