在包含原料马来酸的硫酸溶液中,通过原位阳极氧化法制备了Ti/TiO2膜电极,然后采用极性转换技术在原溶液中电化学合成丁二酸.采用XPS,XRD和SEM分析了膜电极上的元素组成、价态分布和氧化膜的晶相结构及表面形貌.结果表明,阳极氧化膜层内只含有Ti和O两种元素,且Ti均为Ti4+;TiO2氧化膜是金红石相,表观呈现带孔的条纹形貌.通过循环伏安、恒电位阶跃和恒电流电解技术研究了Ti/TiO2原位氧化膜电极的电化学性质,结果表明,该膜电极对马来酸电还原合成丁二酸具有较好的电催化活性.以钛基氧化钌电极(DSA)为阳极,Ti/TiO2原位氧化膜电极为阴极进行恒电流电解实验.结果表明,丁二酸的还原产率为95.94%,电流效率为95.57%,产物纯度为99.28%,熔点为185~187℃.
Ti/TiO2 film electrode was prepared by in-situ anodic oxidation method in a mixture of 1.0 mol/L H2SO4 and 1.0 mol/L maleic acid solution.Then succinic acid was synthesized by technique of switching the polarity in the original solution.Elemental composition and valence state analysis of anodic oxidation film were detected by XPS.The porous structure and rutile structure of TiO2 film were observed by SEM and XRD.Electrochemical performance of the Ti/TiO2 film electrode was investigated by cyclic voltammetry,constant potential step and galvanostatic electrolysis experiments.The results indicated that an excellent electro-catalytic activity for reduction of maleic acid to succinic acid in H2SO4 solution could be confirmed.Galvanostatic electrolysis experiments were carried out on an anode of DSA and a cathode of Ti/TiO2 film electrode at 45 ℃.The experimental results gave the reduction yield of 95.94%,current efficiency of 95.57%,the purity of 99.28% and melting point of 185—187 ℃ for production of succinic acid.