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Title: CO Coverage/Oxidation Correlated with PtRu Electrocatalyst Particle Morphology in 0.3 M Methanol by in situ XAS

Abstract

In situ X-ray absorption spectroscopy (XAS) measurements, including both X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) at the Pt L{sub 3} and Ru K edges, were carried out on three different carbon-supported PtRu electrocatalysts in an electrochemical cell in 1 M HClO{sub 4} with 0.3 M methanol. The CO and OH adsorbate coverage on Pt and Ru were determined as a function of the applied potential via the novel delta XANES technique, and the particle morphology was determined from the EXAFS and a modeling technique. Both the bifunctional and direct CO oxidation mechanisms, the latter enhanced by electronic ligand effects, were evident for all three electrocatalysts; however, the dominant mechanism depended critically on the particle size and morphology. Both the Ru island size and overall cluster size had a very large effect on the CO oxidation mechanism and activation of water, with the bifunctional mechanism dominating for more monodispersed Ru islands, and the direct surface ligand effect dominating in the presence of larger Ru islands.

Authors:
; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
DOE - OFFICE OF SCIENCE
OSTI Identifier:
1019790
Report Number(s):
BNL-95636-2011-JA
Journal ID: ISSN 0013-4651; JESOAN; TRN: US201115%%426
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the Electrochemical Society; Journal Volume: 154; Journal Issue: 5
Country of Publication:
United States
Language:
English
Subject:
10 SYNTHETIC FUELS; ABSORPTION; ABSORPTION SPECTROSCOPY; ELECTROCATALYSTS; ELECTROCHEMICAL CELLS; FINE STRUCTURE; METHANOL; MORPHOLOGY; OXIDATION; PARTICLE SIZE; SIMULATION; SPECTROSCOPY; WATER; national synchrotron light source

Citation Formats

Scott, F., Mukerjee, S, and Ramaker, D. CO Coverage/Oxidation Correlated with PtRu Electrocatalyst Particle Morphology in 0.3 M Methanol by in situ XAS. United States: N. p., 2007. Web. doi:10.1149/1.2709496.
Scott, F., Mukerjee, S, & Ramaker, D. CO Coverage/Oxidation Correlated with PtRu Electrocatalyst Particle Morphology in 0.3 M Methanol by in situ XAS. United States. doi:10.1149/1.2709496.
Scott, F., Mukerjee, S, and Ramaker, D. Mon . "CO Coverage/Oxidation Correlated with PtRu Electrocatalyst Particle Morphology in 0.3 M Methanol by in situ XAS". United States. doi:10.1149/1.2709496.
@article{osti_1019790,
title = {CO Coverage/Oxidation Correlated with PtRu Electrocatalyst Particle Morphology in 0.3 M Methanol by in situ XAS},
author = {Scott, F. and Mukerjee, S and Ramaker, D},
abstractNote = {In situ X-ray absorption spectroscopy (XAS) measurements, including both X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) at the Pt L{sub 3} and Ru K edges, were carried out on three different carbon-supported PtRu electrocatalysts in an electrochemical cell in 1 M HClO{sub 4} with 0.3 M methanol. The CO and OH adsorbate coverage on Pt and Ru were determined as a function of the applied potential via the novel delta XANES technique, and the particle morphology was determined from the EXAFS and a modeling technique. Both the bifunctional and direct CO oxidation mechanisms, the latter enhanced by electronic ligand effects, were evident for all three electrocatalysts; however, the dominant mechanism depended critically on the particle size and morphology. Both the Ru island size and overall cluster size had a very large effect on the CO oxidation mechanism and activation of water, with the bifunctional mechanism dominating for more monodispersed Ru islands, and the direct surface ligand effect dominating in the presence of larger Ru islands.},
doi = {10.1149/1.2709496},
journal = {Journal of the Electrochemical Society},
number = 5,
volume = 154,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}