ELECTROCHEMICAL REDUCTION OF CARBON-DIOXIDE ON DUAL-FILM ELECTRODES MODIFIED WITH AND WITHOUT COBALT(II) AND IRON(II) COMPLEXES

Carbon dioxide has been electrochemically reduced to organic substances on dual-film electrodes modified with and without a metal complex. Polymethylpyrrole/molybdenum blue-modified electrodes yielded methanol, ethanol, and acetone as the reduction products. The substitution of the coated film by the Fe(II)-4,5-dihydroxybenzene-1,3-disulfonate complex-immobilized polyanine/Prussian blue led to the selective formation of lactic acid. Reaction products were found both in the solution and within the coated film, suggesting that the electroreduction of CO2, takes place at active centers existing in the coated film and at the electrode/solution interface. A probable pathway was proposed in which CO2 is hydrogenerated stepwise by H(ads), and various products are generated by the cross-linking of adsorbed intermediates.