CO2 REDUCTION AT PLATINUM, GOLD AND GLASSY-CARBON ELECTRODES IN ACETONITRILE - AN INSITU FTIR STUDY

The reduction of CO2atplatinum, gold and glassy carbon electrodes in acetonitrile was studied using in-situ FTIR. For gold, reduction takes place at potentials below -1.3 V, the major reduction products under the conditions used being CO and formate anion. On glassy carbon, however, CO2 is reduced to CO at only at potentials below -2.2 V. The behaviour of CO2 on platinum is more subtle: at potentials below -1.3 V, products are seen with IR spectra essentially identical to those reported previously. Evidence is presented to show that these products are various forms of partially aquated CO32- that arise not from direct reduction of CO2, but by reduction of adventitious water at platinum, which gives rise to a substantial increase in H-, resulting in dissolution of the CO2. © 1990.