CO 2 electrolysis to multicarbon products at activities greater than 1 A cm −2

Graceful choreography for CO 2 and H 2 O One challenge for efficient electrochemical reduction of carbon dioxide (CO 2 ) is that the gas is hydrophobic, but many of its desirable reactions require water (H 2 O). García de Arquer et al. addressed this problem by combining a copper electrocatalyst with an ionomer assembly that intersperses sulfonate-lined paths for the H 2 O with fluorocarbon channels for the CO 2 . The electrode architecture enables production of two-carbon products such as ethylene and ethanol at current densities just over an ampere per square centimeter. Science , this issue p. 661