Conversion of Carbon Dioxide into Valuable Chemicals through Electrochemical Reduction Using Transition Metal Electrocatalysts

Electrochemical reduction of CO2 is an emerging and current issue for its conversion into valuable product containing high energy density, and simultaneously the reduction helps to reduce the level of CO2 in the atmosphere to maintain within the permissible limit. Among plenty of electro-catalysts copper and gold are efficient and effective catalysts, which are synthesized and applicable for this research work. The metal catalysts (Au and Cu) were prepared in inert environment with different compositions through reduction process from their corresponding precursors. The catalytic performance of CO2 reduction for each composition was performed and resulted good catalytic activity with generation of high current density and relatively small onset potential. The catalytic performance, compositions, morphologies, structure and geometric arrangements were evaluated by electrochemical analysis (LSV, impedance, chronoamperometry & tafel plot), EDS, SEM and XAS respectively. The composite metals showed better selectivity of products (~80% CO) and faradaic efficiencies in addition to the impact of grain size in reduction of CO2. Carbon monoxide, formate, methanol and ethanol are the reduction products, which are detected and quantifiable by chromatographic and spectroscopic techniques considering their physical state of each product.