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.