Hydrogen electrocatalysis by carbon supported Pt and Pt alloys: An in situ X-ray absorption study

Journal Article · Mon Jul 01 00:00:00 EDT 1996 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1836995· OSTI ID:367778

Mukerjee, S; McBreen, J ^[1]

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1. Brookhaven National Lab., Upton, NY (United States)

In situ X-ray absorption spectroscopy (XAS) in 1 M HClO{sub 4} was used to examine the electronic and structural effects of hydrogen adsorption on carbon supported Pt (Pt/C) and Pt alloyed with first row transition metals (Cr, Mn, Fe, Co, and Ni). In the case of Pt/C, potential excursions from the double layer region (0.54 V vs RHE) to 0.0 V caused significant changes in the XAS spectra whereas none was observed for the alloys. The L{sub 3} and L{sub 2} X-ray absorption near edge structure indicated the generation of empty electronic states in the vicinity of the Fermi level due to adsorption of hydrogen, and the L{sub 3} extended X-ray absorption fine structure indicated an increase in the coordination number of the first Pt-Pt shell from 9 to 11. The latter was attributed to a reversible surface restructuring process. Alloying of the Pt suppresses both the electronic and structural effects at 0.0 V. A comparison of the electrochemical kinetics for hydrogen oxidation by these electrocatalysts in a proton exchange membrane fuel cell indicated that alloying of the Pt had insignificant effects on the kinetics.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 367778
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 7 Vol. 143; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
ABSORPTION SPECTRA
ALCOHOL FUEL CELLS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHROMIUM ALLOYS
COBALT ALLOYS
ELECTROCATALYSTS
ELECTRONIC STRUCTURE
HYDROGEN
IRON ALLOYS
MANGANESE ALLOYS
METHANOL
MORPHOLOGICAL CHANGES
NICKEL ALLOYS
OXIDATION
PLATINUM
PLATINUM ALLOYS
SOLID ELECTROLYTE FUEL CELLS
SORPTION