Electrochemically converting carbon monoxide to liquid fuels by directing selectivity with electrode surface area

Using renewable electricity to convert CO/CO2 into liquid products is touted as a sustainable process to produce fuels and chemicals, yet requires further advances in electrocatalyst understanding, development and device integration. The roughness factor of an electrode has generally been used to increase total rates of production, although rarely as a means to improve selectivity. Here we demonstrate that increasing the roughness factor of Cu electrodes is an effective design principle to direct the selectivity of CO reduction towards multicarbon oxygenates at low overpotentials and concurrently suppressing hydrocarbon and hydrogen production. The nanostructured Cu electrodes are capable of achieving almost full selectivity towards multicarbon oxygenates at an electrode potential of only –0.23 V versus the reversible hydrogen electrode. The successful implementation of this catalytic system has enabled an excellent CO reduction performance and elucidated viable pathways to improve the energy efficiency towards liquid fuels in high-power conversion electrolysers. The roughness factor of an electrode has been generally used to increase total rates of production, though rarely as a means to improve selectivity. Now, Jaramillo, Hahn and co-workers direct the selectivity of CO reduction to multicarbon oxygenates at low overpotentials by increasing the roughness factor of nanostructured Cu electrodes.