the National Natural Science Foundation of China(21373135);Science Foundation of Ministry of Education of China(413064);Program of Introducing Talents of Discipline to Universities, China ("111 Project")(B13018)
Institute of Fuel Cells, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
Abstract:
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.
