Electrochemical Reduction of Carbon Dioxide Dissolved under High Pressure III. In Nonaqueous Electrolytes

Abstract

DMSO was used as an aprotic solvent, and tetraalkylammonium salts such as Et4NClO4, Et4NBr, and Bu4NBr were used as a solute. Various solid state metals such as In, Sn, Pb, and Zn were used as the cathode. When Pb was used, the main redn. product was oxalic acid. In Et4NClO4 and Et4NBr, solns. such acids as tartaric, malonic, glycolic, propionic, butyric, and formic acids were formed in addn. to oxalic acid. In Bu4NBr soln., the main product was oxalic, formic, and tartaric acid. When In, Zn, and Sn were used as cathodes, the main redn. product was CO,and oxalic, malonic and formic acid were also found in low concn. By study of the cathodic polarization curves, it was concluded that various higher carboxylic acids cited above were formed via formation of oxalic acid as an intermediate. [on SciFinder (R)]