【摘要】 以乙二醇代替常规的异丙醇为分散溶剂,H2PtCl6为前驱体溶剂,甲醛为还原剂,采用改进浸渍还原法制备Pt/C催化剂,用XRD,TEM和XPS对其进行表征.改进浸渍还原法容易制备高分散度Pt/C催化剂,催化剂Pt粒径大小可通过改变溶液pH值控制,pH值从1.6增加至11.3,铂纳米粒子的平均粒径由3.3nm减小到1.8nm.pH值11.3时催化剂中Pt(0),Pt(II)和Pt(IV)的含量分别为43.3%,30.8%和25.9%.选择不同Pt粒径大小的Pt/C催化剂与聚四氟乙烯(PTFE)一起负载于泡沫镍(FN),得到Pt/C/FN疏水催化剂,考查其对氢水液相交换反应的催化活性,Pt粒径越小,催化剂活性越高.更多还原

【Abstract】 Pt nanoparticles with different mean sizes supported on XC-72R were prepared by an improved impreganation-reduction method, using HCHO as a reducing reagent and ethylene glycol as a dispersing solvent of H2PtCl6 instead of isopropyl alcohol. The Pt/C catalysts were characterized by XRD, TEM and XPS. Highly-dispersed Pt/C catalysts could be prepared by the improved impreganation-reduction method easily, and the size of Pt particles could be controlled by changing the solution pH. TEM examinations show that the mean Pt particle size decreased from 3.3 to 1.8 nm with the increase of pH values from 1.6 to 11.3. The contents of Pt(0), Pt(II) and Pt(IV) of Pt/C catalysts, fabricated at pH 11.3, are 43.3%, 30.8% and 25.9%, respectively. Then polytetrafluoroethylene (PTFE) and Pt/C catalysts with different mean sizes of Pt particles were supported on foamed nickel (FN) to obtain hydrophobic Pt/C/FN catalysts. The catalytic ac- tivities of the hydrophobic catalysts were investigated for hydrogen-water liquid phase exchange reaction. The catalytic activity increased with the decrease of the mean size of Pt particles of Pt/C/FN catalysts.更多还原