The Electrolytic Reduction of Maleic Acid to Succinic Acid in Acid Solution

The electrolytic reduction of maleic acid in solutions of sulfuric acid has been studied at cathodes of copper, zinc, cadmium, mercury, aluminum, tin, lead, bismuth, iron, cobalt, and nickel. The best yield of succinic acid was obtained at a mercury cathode. The activities of copper and nickel cathodes were affected by etching. Changes in the physical structures of other cathodes, with the possible exception of zinc, were transient in effect.