Tunable Production\nof Syngas via Pulsed-Potential\nElectrolysis of CO<sub>2</sub> over Single-Crystal Cu(100)

Obtaining syngas from the electrochemical reduction of\nCO<sub>2</sub> has been considered an economical and promising solution\nfor energy\nand environmental sustainability. Cu-based catalysts have been attracting\ngreat attention due to their low cost and easy accessibility, while\ntuning the selectivity toward specific products is a critical issue.\nIn this work, a pulsed-potential strategy coupled with a low-reduction\noverpotential is applied to (100) single-crystal Cu foils. Only H<sub>2</sub> and CO are observed under the bias of a low-reduction potential.\nBy tuning the pulse width and anodic potential, controllable syngas\nwith a broad range from ∼97:5 to ∼5:14 can be obtained\nwith the same low cathodic potential. Based on various characterization\nresults before and after pulse electrolysis, the enhanced CO production\nis attributed to the in situ-generated Cu<sup>+</sup> species and\nroughened surface, as well as the modulation of local pH and CO<sub>2</sub> concentration near the electrode.