Investigation of Graphene Supported Au-Cu Nanoparticles As Electrocatalyst for CO2 Electro-Reduction

Carbon dioxide (CO2) is the most common greenhouse gas in our planet. Reduction of CO2 production and conversion of CO2 into useful materials at the same time is necessary. CO2 conversion using electro-catalysis can be controlled by electrode potentials and the reaction temperature. Also the electrochemical reaction systems are compact, modular and easy for scale-up applications. Cu-based composites with different compositions can seriously influence its electrocatalytic performance toward CO2 reduction reaction. In the present study, a rapid microwave heating method was used to prepare the graphene or carbon supported Au-Cu nanoparticles as electrocatalysts for the electrochemical reduction of CO2. The morphology and composition of the fabricated catalysts were examined using Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The activity of the fabricated catalysts for CO2 electro-reduction was examined using cyclic voltammetry and linear sweep voltammetry in acidic (pH=1.7), neutral (pH=6.3) and alkaline (pH=10.3) media. It was found that the graphene or carbon supported Au-Cu catalysts show a similar electrocatalytic activity for the electro-reduction of CO2 in the acidic media, whereas the graphene supported Au-Cu catalyst shows a higher activity in the neutral and alkaline media as compared with that of carbon supported Au-Cu catalyst.