Strong Boron–Carbon Bonding Interaction Drives CO₂ Reduction to Ethanol over the Boron-Doped Cu(111) Surface: An Insight from the First-Principles Calculations

Facile conversion of CO 2 into useful multicarbon products is of broad interest in the field of energy storage and controllable carbon emission. However, electrochemical CO 2 reduction to ethanol on the Cu(111) surface is limited to the high applied potential and low selectivity. Herein, we demonstrate that the Cu-based electrocatalysts modified by boron (B) single-atom greatly reduce the thermodynamic energy barrier and improve selectivity relative to pristine Cu(111) in the hydrogenation of CO 2 to ethanol. Electronic structure analysis reveals that the doped B atom, as a charge transfer medium, not only works in supplying electrons to stabilize the intermediates but also undergoes distinct reaction paths compared with pristine Cu(111) to improve the selectivity of ethanol. Moreover, the formation of the robust B–C bond and the unique isomerization step keep the C atoms of the intermediates in an opposite-charged state, which makes C–C coupling facile to generate ethanol. These findings would be very useful to guide the search for a new catalyst for electrochemical CO 2 reduction with high ethanol selectivity based on the abundant Cu-based materials.