%0 Journal Article
%T <br>
%A 朱凤鹃
%A 沈水云
%A 章俊良
%A 罗柳轩
%J 物理化学学报
%D 2016
%R 10.3866/PKU.WHXB201509144
%X 通过一种结合了CO辅助合成Pt3Ni纳米立方粒子和单原子层Cu壳欠电位沉积再置换为Pd的方法，成功制备出了具有单原子层Pd壳和Pt3Ni纳米立方粒子核结构的Pt3Ni@Pd/C催化剂。电感耦合等离子体元素分析、X射线衍射和透射电子显微镜法被用于研究表征此种Pt3Ni@Pd/C催化剂，结果显示大部分Pt3Ni纳米粒子的表面都由{100}族的晶面所构成。而且在这些{100}族的晶面上，单原子层Pd壳通过电沉积的外延生长，也获得了{100}族的晶面。本文进一步对Pt3Ni@Pd/C作为甲酸氧化电催化剂的性能进行了研究，并与商业Pd/C和原Pt3Ni/C催化剂进行了比较。结果显示，由于Pt3Ni@Pd/C的单原子层Pd壳的结构和所暴露出的Pd{100}族的晶面，Pt3Ni@Pd/C催化剂具有优异的甲酸氧化电催化性能。与原Pt3Ni/C催化剂相比较，Pt3Ni@Pd/C催化剂的贵金属质量比活性提高到了7.5倍。此外，与商业Pd/C催化剂相比，Pt3Ni@Pd/C催化剂的比表面活性和Pd质量比活性也分别提高到了2.5和8.3倍。<br>We designed and synthesized carbon-supported cubic Pt3Ni nanoparticles (NPs) with Pd monolayer shells (Pt3Ni@Pd/C) by a two-step method: generally, CO-assisted preparation of cubic Pt3Ni NPs, Pd monolayer deposition through underpotential deposition of a Cu monolayer, and displacement of Cu with Pd. The as-synthesized Pt3Ni@Pd/C catalyst was characterized with inductively coupled plasma elemental analysis, X-ray diffraction, and transmission electron microscopy. Most Pt3Ni NPs had a cubic nanostructure enclosed by {100} facets, on which the Pd monolayer shells were deposited epitaxially via electrodeposition, by which the Pd monolayers gained the crystallographic orientation of the {100} facets. We then used Pt3Ni@Pd/C as an electrocatalyst for formic acid oxidation (FAO), comparing it with commercial Pd/C and the pristine Pt3Ni/C catalysts. The Pt3Ni@Pd/C exhibited superior electrocatalytic performance because of its monolayer structure and exposed Pd{100} facets. The noble-metal mass activity of the Pt3Ni/C with the deposited Pd monolayer shell was 7.5 times greater than that of the Pt3Ni/C catalyst alone. Moreover, the area-specific and Pd mass activities of Pt3Ni@Pd/C were 2.5 and 8.3 times greater than those of the commercial Pd/C catalyst, respectively
%U http://www.whxb.pku.edu.cn/CN/Y2016/V32/I1/337