Electrocatalytic reduction of carbon dioxide on SnO2/MWCNT in aqueous electrolyte solution

This communication reports the activity of SnO2/MWCNT (multi-walled carbon nanotubes) electrocatalysts for CO2 reduction in an aqueous electrolyte solution using two compartment electrochemical cell. The effect of metal loading of the powdered catalysts (working electrode) on the reduction capabilities of CO2 are studied, under ambient pressure and room temperature conditions. Electrochemical techniques such as linear sweep voltammetry and chronoamperometry are employed to get the current response (current density) for CO2 reduction at different applied potentials. Current densities (C.D.) and the faradaic efficiencies (F.E.) of the products are the key performance indicators for any electrochemical process. The higher current densities and faradaic efficiencies for CO2 reduction are obtained with the optimum SnO2 content (20% by weight) on the high surface area MWCNT support. The 20% SnO2/MWCNT catalyst shows remarkable activity for CO2 conversion to formate with F.E. of c.a. 27.2% at a potential of −1.7V vs. SCE (Saturated Calomel Electrode). The higher activity is attributed to the uniform dispersion and more availability of active sites for CO2 reduction.