Polydopamine Functionalized Cu Nanowires for Enhanced CO2 Electroreduction Towards Methane

Electrochemical reduction of CO2 provides an ideal approach to convert the greenhouse gas into fuels under mild conditions. Copper electrodes are capable of producing significant amounts of hydrocarbons, but the selectivity to convert CO2 into methane (CH4) remains low. Here, we prepared functionalized Cu nanowire electrodes by coating polymers (polydopamine, PDA) and experimentally verified that the functionalized CuNWs indeed shows 2.3 times higher CH4 selectivity compared with that of CuNWs. The PDA functionalized CuNWs catalyst remains catalytically stable for in excess of 14 hours. We experimentally reveal that the amino groups could be responsible for the capture and delivery of protons for the hydronation of CO* intermediates and phenolic hydroxyl groups for the stabilization of CO* intermediates. The results provide us insights into a new approach to optimize the electrochemical methanation of CO2 by polymers that contain abundant functional groups.