Standard Article

Pt alloys as oxygen reduction catalysts

Fuel Cell Technology and Applications

Polymer electrolyte membrane fuel cells and systems (PEMFC)

Electro-catalysts

  1. D. Thompsett

Published Online: 15 DEC 2010

DOI: 10.1002/9780470974001.f303041

Handbook of Fuel Cells

Handbook of Fuel Cells

How to Cite

Thompsett, D. 2010. Pt alloys as oxygen reduction catalysts. Handbook of Fuel Cells. .

Author Information

  1. Johnson Matthey Technology Centre, Reading, UK

Publication History

  1. Published Online: 15 DEC 2010

Abstract

The use of carbon-supported Pt alloy catalysts for phosphoric acid fuel cells (PAFC) is well established. In comparison with Pt-only catalysts, Pt alloy catalysts offer greater oxygen reduction activity and durability. In contrast, the introduction of Pt alloy catalysts for proton exchange membrane fuel cells (PEMFC) is in its infancy, despite having been shown to offer better performance to Pt-only catalysts. Since the first reports of the use of Pt alloys as cathode catalysts in PEMFCs in 1992, surprisingly little further work has been reported. However, carbon-supported Pt alloys have been shown to give superior performance to Pt in practical fuel cell hardware, as well as showing good durability. The mechanisms for enhanced activity of Pt alloys for oxygen reduction have been debated for the last 20 years, with many ideas proposed. However, more recently, the use of in situ characterization techniques, especially X-ray adsorption spectroscopy, has shed light on the differences between Pt and Pt alloys at the potentials of oxygen reduction. It has been shown that alloys show differences in electronic and structural properties, as well as inhibited chemisorption of oxygenated species and stability of surfaces to reconstruction.

Keywords:

  • electrocatalysis;
  • cathode;
  • Pt;
  • Pt alloy;
  • oxygen reduction;
  • solid polymer fuel cell