Selective electroreduction of pyruvic acid on lead electrode in acid medium

This work reports the electrochemical reduction of pyruvic acid, which contains a carbonyl group more reducible than its carboxylic entity. The electrode potential and the concentration of the starting substrate seemed to be the factors that control the electrochemical production of the competitive reaction products. In fact, lactic acid was mainly obtained on a lead electrode in sulfuric acid for low concentrations of pyruvic acid while 2,3-dimethyl tartaric acid was selectively formed by electrohydrodimerization of a high amount of pyruvic acid. During the cathodic reduction of pyruvic acid in sulfuric acid solution, the effects of electrode potential and pyruvic acid concentration on the selectivity towards the formation of lactic acid were systematically studied.