Transmission electron microscopy studies of the nanoscale structure and chemistry of Pt50Ru50 electrocatalysts

Microsc Microanal. 2002 Feb;8(1):50-7. doi: 10.1017/S1431927602010097.

Abstract

The structural and chemical heterogeneity of 2.5-nm Pt50Ru50 electrocatalysts was studied by transmission electron microscopy using selected area diffraction, lattice imaging, electron-energy loss spectroscopy, and energy-dispersive X-ray spectroscopy. The catalysts with the highest methanol oxidation activities exhibit oxidation-induced phase separation on the nanoscale to from Pt-rich metal embedded in Ru-rich hydrous and anhydrous oxide. Reduction of the oxide-on metal samples produces a true bimetallic face-centered cubic Pt50Ru50 alloy, with 275 times lower oxidation activity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alloys / chemistry*
  • Catalysis
  • Electron Probe Microanalysis
  • Mass Spectrometry / methods
  • Methanol / metabolism
  • Microscopy, Electron / instrumentation
  • Microscopy, Electron / methods*
  • Nanotechnology / instrumentation
  • Nanotechnology / methods*
  • Oxidation-Reduction
  • Platinum / chemistry*
  • Ruthenium / chemistry*

Substances

  • Alloys
  • Platinum
  • Ruthenium
  • Methanol