Research on Chemical Intermediates

, Volume 32, Issue 5, pp 543–559

Platinum submonolayer-monolayer electrocatalysis: An electrochemical and X-ray absorption spectroscopy study

  • Kotaro Sasaki
  • Junliang Zhang
  • Jia Wang
  • Francisco Uribe
  • Radoslav Adzic
Article

DOI: 10.1163/156856706777973646

Cite this article as:
Sasaki, K., Zhang, J., Wang, J. et al. Res Chem Intermed (2006) 32: 543. doi:10.1163/156856706777973646

Abstract

A new Pt monolayer electrocatalyst concept is described and the results of electrochemical and X-ray absorption spectroscopy (XAS) studies are presented. Two new methods that facilitate the application of this concept in obtaining ultra-low-Pt-content electrocatalysts have been developed. One is the electroless (spontaneous) deposition of a Pt submonolayer on Ru nanoparticles, and the other is a deposition of a Pt monolayer on Pd nanoparticles by redox displacement of a Cu adlayer. The Pt submonolayer on Ru (PtRu20) electrocatalyst demonstrated higher CO tolerance than commercial catalysts under conditions of rotating disk experiments. The long-term stability test showed no loss in performance over 870 h using a fuel cell operating under real conditions, even though the Pt loading was approximately 10% of that of the standard Pt loading. In situ XAS indicated an increase in d-band vacancy of deposited Pt, which may facilitate partly the reduced susceptibility to CO poisoning for this catalyst. The kinetics of O2 reduction on a Pt monolayer on Pd nanoparticles showed a small enhancement in comparison with that from a Pt nanoparticle electrocatalyst. The increase in catalytic activity is partly attributed to decreased formation of PtOH, as shown by XAS experiments.

Keywords

Platinum monolayer electrocatalystsubmonolayernanoparticleX-ray absorption spectroscopy

Copyright information

© VSP 2006

Authors and Affiliations

  • Kotaro Sasaki
    • 1
  • Junliang Zhang
    • 1
  • Jia Wang
    • 1
  • Francisco Uribe
    • 2
  • Radoslav Adzic
    • 1
  1. 1.Department of Materials ScienceBrookhaven National LaboratoryUptonUSA
  2. 2.Los Alamos National LaboratoryLos AlamosUSA