Electrochemical behaviorof CO2 on copper electrode

The electrochemical reduction of CO2 on copper electrode was investigated in acetonitrile(MeCN) dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) containing 0.1 mol/L tetraethylammonium bromioe(TEABr) by cyclic voltammetry and chronocoulometry at 298 K and under atmospheric pressure. There were obviously irreversible one-electron reduction peaks after saturated with CO2 on copper electrode in three solvents, which generated anion radical of CO2. The influence of scan rate was also studied by cyclic voltammetry. The diffusion coefficients of CO2 in MeCN, DMF and DMSO were 8.981 x 10(-6), 1.019 x 10(-6) and 1.032 x 10(-6) cm(2)/s and the transfer coefficients were 0.064, 0.042 and 0.059, respectively. These results show that the electroreduction of CO2 was an irreversible diffusion controlled process.