Pd-Pt Bimetallic Nanodendrites with High Activity for Oxygen Reduction
Byungkwon Lim,1
Majiong Jiang,2
Pedro H. C. Camargo,1
Eun Chul Cho,1
Jing Tao,3
Xianmao Lu,1
Yimei Zhu,3
Younan Xia1,*
Controlling the morphology of Pt nanostructures can provide
a great opportunity to improve their catalytic properties and
increase their activity on a mass basis. We synthesized Pd-Pt
bimetallic nanodendrites consisting of a dense array of Pt branches
on a Pd core by reducing K
2PtCl
4 with L-ascorbic acid in the
presence of uniform Pd nanocrystal seeds in an aqueous solution.
The Pt branches supported on faceted Pd nanocrystals exhibited
relatively large surface areas and particularly active facets
toward the oxygen reduction reaction (ORR), the rate-determining
step in a proton-exchange membrane fuel cell. The Pd-Pt nanodendrites
were two and a half times more active on the basis of equivalent
Pt mass for the ORR than the state-of-the-art Pt/C catalyst
and five times more active than the first-generation supportless
Pt-black catalyst.
2 Department of Chemistry, Washington University, St. Louis, MO 63130, USA.
3 Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
* To whom correspondence should be addressed. E-mail: xia{at}biomed.wustl.edu
