Published online by Cambridge University Press: 28 June 2013
We have studied the electrochemical reduction of CO2 to produce short chain hydrocarbons and alcohols using supported Cu2O electrocatalysts. The catalysts are prepared using Cu2O nanoparticles formed by chemical reduction of aqueous CuCl2 mixed with polyethylene glycol surfactant, followed by addition of NaOH and L-ascorbic acid (sodium). The nanoparticles are then added to a Nafion/ethanol solution and coated onto a carbon fiber support. When tested used for CO2 electroreduction at −1.5 V(NHE), the Cu2O particles are reduced to metallic Cu, but the hydrocarbon product distribution remains different from that reported for conventional metallic Cu electrodes. Ethylene is the major hydrocarbon produced, with a Faradaic efficiency around 25%, while the efficiency for CH4 formation is reduced to around 1%. The major alcohol product is ethanol, with a Faradaic efficiency around 6%. The relative formation rates of the individual products are discussed in terms of the relevant branch points in recent computational models for the overall reaction mechanism.