Jump to main content
Jump to site search

Issue 9, 2004
Previous Article Next Article

Influence of atomic ordering on the electrocatalytic activity of Pt–Co alloys in alkaline electrolyte and proton exchange membrane fuel cells

Author affiliations

Abstract

Carbon-supported Pt–Co alloy catalysts with Co contents of 10–50 wt% have been synthesized by reducing aqueous Co2+ ions with borohydride or precipitating as hydroxide in the presence of a commercially available carbon-supported Pt catalyst followed by heat treatment in a 90% Ar–10% H2 mixture at 900 °C for 1 h. X-Ray diffraction indicates the Pt–Co alloys thus obtained to have the ordered Pt3Co or PtCo type structures or the disordered Pt type structure depending on the Co content. High resolution transmission electron microscopy (HRTEM) studies also confirm the formation of ordered structures. Structural analysis of the products after annealing at various temperatures 500 ≤ T ≤ 900 °C for 1 h suggests the ordering to be maximized for an annealing temperature of around 650 °C. Evaluation of the Pt–Co/C alloy catalysts for oxygen reduction in half cells employing KOH as the electrolyte and in proton exchange membrane fuel cells indicates that the alloys with the ordered Pt3Co or PtCo type structures have higher catalytic activity with lower polarization losses and higher power densities than Pt or disordered Pt–Co alloys. With the ordered phases, the activity increases with the extent of ordering. The enhanced catalytic activity is explained based on optimal structural and electronic features consisting of optimum number of Pt and Co nearest neighbors, Pt–Pt distance, and d-electron density in Pt.

Graphical abstract: Influence of atomic ordering on the electrocatalytic activity of Pt–Co alloys in alkaline electrolyte and proton exchange membrane fuel cells

Back to tab navigation

Publication details

The article was received on 20 Jan 2004, accepted on 11 Mar 2004 and first published on 05 Apr 2004


Article type: Paper
DOI: 10.1039/B400968C
J. Mater. Chem., 2004,14, 1454-1460

  •   Request permissions

    Influence of atomic ordering on the electrocatalytic activity of Pt–Co alloys in alkaline electrolyte and proton exchange membrane fuel cells

    L. Xiong and A. Manthiram, J. Mater. Chem., 2004, 14, 1454
    DOI: 10.1039/B400968C

Search articles by author

Spotlight

Advertisements