Electrochemical Synthesis of Succinic Acid at a TiO2 Film Electrode Prepared by In-Situ Anodic Oxidation

TiO2film was prepared by in-situ anodic oxidation on a polished titanium sheet in a mixed acid solution containing 1.0 mol/l sulfuric acid and 1.0 mol/l maleic acid. By means of polar conversion technology, succinic acid was synthesized using a TiO2film as cathode in the original solution. The reduction yield and current efficiency of succinic acid were 99.36% and 97.52%, respectively. The elemental composition, valence state analysis and superficial morphology of TiO2film cathode before and after electrolysis were characterized by XPS and SEM. The electrocatalytic properties of TiO2film electrode towards the electrocatalytic reduction of maleic acid to succinic acid were evaluated by CV and galvanostatic electrolysis experiments. Experimental evidence was presented that porous TiO2film cathode exhibited powerful electrocatalytic activity for the reduction of maleic acid. Furthermore, a synergistic effect of low valent titanium of Ti(III) and chemisorbed hydrogen (H)Ti was proposed for probable reductive mechanism of malaeic acid to succinic acid.