在甲醇溶剂中,利用SnCl2作为还原剂,通过控制反应条件制备了具有不同粒径Pt粒子的炭载Pt(Pt/C)催化剂.X射线衍射(XRD)和透射电子显微镜(TEM)的结果表明,Pt/C催化剂中Pt粒子具有高度的均一性和良好的分散度.电化学研究结果显示,对于甲酸的电催化氧化,Pt/C催化剂存在着明显的粒径效应.当Pt粒子粒径为3.2nm时,Pt/C催化剂对甲酸的电催化氧化活性最佳.Pt/C催化剂对甲酸氧化的粒径效应与其表面含氧基团含量、Pt粒子的比表面积及相对结晶度相关.
In methanol solvent, using SnC12 as reducing agent, carbon supported Pt (Pt/C) catalysts with different size of Pt particles were prepared. X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements demonstrated that in the obtained Pt/C catalysts, the Pt particles have great uniformity and good dispersion. The electrochemical experiments indicated that the effect of average particle size of Pt/C catalysts for formic acid oxidation is obvious. The Pt/C catalyst with 3.2 nm average size of the Pt particles exhibited the optimal electrocatalytic performance for formic acid oxidation. This effect of particle size may be related to the quantity of the oxygen-containing species on the surface of the catalyst, the apparent surface area and the relative crystallinity of the platinum particles.