Copper/Polyaniline Interfaces Confined CO 2 Electroreduction for Selective Hydrocarbon Production

Polyaniline (PANI) provides an attractive organic platform for CO electrochemical reduction due to the ability to adsorb CO molecules and in providing means to interact with metal nanostructures. In this work, a novel PANI supported copper catalyst has been developed by coupling the interfacial polymerization of PANI and Cu. The hybrid catalyst demonstrates excellent activity towards production of hydrocarbon products including CH and C H , compared with the use of bare Cu. A Faradaic efficiency of 71.8 % and a current density of 16.9 mA/cm were achieved at -0.86 V vs. RHE, in contrast to only 22.2 % and 1.0 mA/cm from the counterpart Cu catalysts. The remarkably enhanced catalytic performance of the hybrid PANI/Cu catalyst can be attributed to the synergistic interaction between the PANI underlayer and copper. The PANI favours the adsorption and binding of CO molecules via its nitrogen sites to form *CO intermediates, while the Cu/PANI interfaces confine the diffusion or desorption of the *CO intermediates favouring their further hydrogenation or carbon-carbon coupling to form hydrocarbon products. This work provides insights into the formation of hydrocarbon products on PANI-modified Cu catalysts, which may guide the development of conducting polymer-metal catalysts for CO electroreduction.