Improved yields of oxalate, glyoxylate and glycolate from the electrochemical reduction of carbon dioxide in methanol

Abstract

The yields of oxalate and especially of glyoxylate and glycolate were enhanced by the use of methanol containing hydroxylamine and tetramethylammonium chloride in the controlled potential electrochemical reduction of carbon dioxide at a lead electrode. An eightfold increase in the solubility of CO2 was found compared with water so that the initial concentration was 4.48 × 10−3m. Products were mainly glyoxylate (up to 9.7 × 10−3m at −2.0 V) and glycolate (up to 6.6 × 10−3m at −2.3 V) with some oxalate (up to 1.3 × 10−4m at −1.7 V) depending on the time and electrode potential. Very little formate was produced. Current densities were about 30 A m−2.