Promoting CO electroreduction on CuO nanowires with a hydrophobic Nafion overlayer.

Copper-based materials could produce a series of products through the CO electroreduction reaction, and are regarded as the most promising catalysts to produce fuels and value-added chemicals using renewable energy sources. However, the competitive hydrogen evolution reaction (HER) is a daunting challenge for the selectivity of carbonaceous products. Here, a hydrophobic electrode surface was constructed by modifying the CuO nanowire electrode with a thick Nafion overlayer, which exhibited enhanced selectivity toward the CO RR (especially for CO) and suppressed HER activity. This work highlights the importance of hydrophobicity in the selectivity of CO reduction and hints at the additional role of Nafion in powder-based catalyst electrodes.