Effect of a thermal treatment on the activity of carbon-supported Pt, Pt+W and Pt+Mo electrocatalysts for methanol oxidation reactions


Gokagac G., Leger J., Hahn F.

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES, vol.56, no.12, pp.1306-1314, 2001 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 56 Issue: 12
  • Publication Date: 2001
  • Title of Journal : ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES
  • Page Numbers: pp.1306-1314

Abstract

Previous studies on carbon supported Pt, Pt+W and Pt+Mo indicated that Pt+Mo was the most active electrocatalyst at low potentials and that Pt+W has similar properties as pure Pt in methanol oxidation. Those samples were thermally treated at 900 degreesC in a hydrogen gas atmosphere for 6 hours to observe the effect on metal particle sizes and on their distribution on carbon support. It was found that thermally treated Pt+Mo/XC-72 remains the most active catalyst at all potentials compared to the other heated samples. The heat treatment caused the sintering of small particles leading to a decrease in activity of the catalysts except Pt+Mo/XC-72. The heat treated samples were characterised by voltammetry, X-ray diffraction, transmission electron microscopy and energy dispersive X-ray analysis techniques. The methanol oxidation reaction was followed by in-situ FTIR spectroscopy to identify products and adsorbed species on the surface of electrode.