中文摘要：

研究了PEG-丙酮体系中光化学合成Pd纳米粒子并在同一体系内在获得的Pd纳米粒子表面光化学还原Pt（IV）离子获得Pd核@Pt壳纳米粒子。通过改变Pd晶种对Pt（IV）的比例,能够有效调节复合粒子的Pt壳厚度。经HR-TEM和XPS分析,结果表明,获得的纳米粒子的平均粒径为5.3~7.1 nm,具有核-壳复合结构。电化学分析表明Pd：Pt摩尔比1：1、4：1的Pt核@Pt壳纳米粒子具有与Pt相似的催化活性和稳定性,且成本更低,可能被用作直接甲醇燃料电池阳极催化材料。

英文摘要：

In the PEG-acetone solution system, the Pd@Pt core-shell nanoparticles were prepared by photochemical reduction of Pt（IV） on the surface of Pd nanoparticles which were firstly in-situ synthesized as the seed by a photochemical method. The thickness of Pt shell of the composite particles could be efficiently adjusted by changing the molar ratio of Pd seed to Pt（IV）. Core-shell composite structure of the obtained nanoparticles with average diameter in the range of 5.3-7.1 nm was confirmed by HR-TEM and XPS. The electrochemical tests indicate that Pd@Pt core-shell nanoparticles, in which Pd： Pt is 1：1 or 1：4, have the similar catalytic activity and the stability to those of Pt, while lower cost. Therefore, they can be used for anode catalyst materials of direct methanol fuel cell.