高分散Pt-TiO_2/C催化剂对甲醇的电催化氧化

Electrooxidation of methanol on highly dispersed Pt-TiO_2/C catalysts

采用TiO2溶胶法,在三种不同条件下制备了碳载Pt-TiO2(Pt-TiO2/C)催化剂。通过XRD衍射,循环伏安法(CV),线性扫描法(LSV)和计时电流法(CA)对Pt-TiO2/C催化剂的结构及其对甲醇的电氧化特性进行了研究。结果表明不同条件制备的催化剂中,TiO2的结晶度不同,Pt的粒径不同,对甲醇的电催化氧化的活性也不同。其中加入聚乙二醇形成的TiO2溶胶以甲酸为还原剂,在乙二醇体系中制备的Pt-TiO2/C催化剂中Pt的粒径小,分布均匀,对甲醇的氧化具有较高的电催化活性。甲醇在该催化剂上的氧化电流密度分别是采用硝酸或醋酸方法的1.08倍和1.43倍。

Carbon supported Pt-TiO2 catalysts were prepared by colloid method on three different conditions.The Home-made Pt-TiO2/C catalysts were used for methanol oxidation in acidic solution.The catalysts prepared have been characterized by powder X-ray diffraction（XRD）,cyclic voltammetry（CV）,linear sweep voltammetry（LSV）and Amperometric I-t techniques（CA）.It was found that addition of TiO2 to Pt/C catalyst effectively improved the elestrooxidation activity of the catalysts.The prepared conditions affected the particle size,the distribution of Pt on carbon support,and therefore the electrocatalytic oxidation activity for methanol.The catalyst,which was prepared with colloidal TiO2 formed by adding polyethylene glycol and HCOOH as reductant,has smallest particle size,homogeneous distribution of Pt in carbon and the highest electrocatalytic oxidation activity for methanol in glycol ethylene among the catalysts prepared.The electrocatalytic activity for the catalyst added polyethylene glycol is 1 .08 times and 1.43 times higher than that for the catalysts with nitrate and acetic acid alone,respectively.