(24b) Electroreduction of Carbon Dioxide to Hydrocarbons Using Copper Nanoparticles' Electrode

A selective electro-reduction process of carbon dioxide in a three-phase system of gas-liquid-solid using a copper nanoparticle electrode is reported.  This electrode was prepared by the surfactant-assisted hydrothermal reduction process with continuous ultra sonication. Prior to the electrochemical reduction of carbon dioxide, the gas was first absorbed in an organic-aqueous phase followed by adsorption on the surface of the copper nano electrode. The large surface area of the electrode and the pH of the solution both affect the electroreduction of carbon dioxide. The main products obtained were formic acid, ethylene, butane, methane and hydrogen with Faradic efficiencies of 27%, 10.5%, 0.3% and 36%, respectively. These faradic efficiencies were found to increase with an increase of: the organic to aqueous volume ratio, the solution temperature, the concentration of the electrolyte and the potential applied. The maximum conversion achieved was 22%.