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Title: Equilibrated adsorption of CO on silica-supported Pt catalysts

Abstract

Microcalorimetric and infrared spectroscopic studies of CO adsorption on Pt/SiO{sub 2} were conducted at temperatures from 298 to 673 K. The adsorption of CO on silica-supported Pt is equilibrated at 673 K, and the microcalorimetric and spectroscopic results obtained at this elevated temperature are in agreement with results reported for Pt(111) at 300 K. The heat of CO adsorption decreases with coverage from the initial value of 190--180 kJ/mol to 75 kJ/mol at the saturation CO coverage of 0.7 ML. In addition, the IR band for CO adsorbed on atop sites shifts to higher wave numbers, and the ratio of integral absorbances of bridge-bonded and atop-bonded species changes with CO coverage. At temperatures lower than 673 K, the adsorption of CO on Pt/SiO{sub 2} is not equilibrated, and the microcalorimetric and IR spectroscopic data are essentially independent of the apparent CO coverage. A Monte Carlo simulation model was used to consolidate data for CO adsorption on Pt/SiO{sub 2} and Pt(111). The simulation was based on a set of parameters describing the energetics for the formation of atop- and bridge-bonded CO species on a clean surface and lateral pairwise interactions between these species on a two-dimensional hexagonal lattice representing a Pt(111)more » surface.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison, WI (US)
OSTI Identifier:
20050846
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical
Additional Journal Information:
Journal Volume: 104; Journal Issue: 17; Other Information: PBD: 4 May 2000; Journal ID: ISSN 1089-5647
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; CARBON MONOXIDE; ADSORPTION; PLATINUM; CATALYST SUPPORTS; SILICA; ADSORPTION HEAT; SPECTROSCOPY

Citation Formats

Podkolzin, S.G., Shen, J., Pablo, J.J. de, and Dumesic, J.A. Equilibrated adsorption of CO on silica-supported Pt catalysts. United States: N. p., 2000. Web. doi:10.1021/jp993833o.
Podkolzin, S.G., Shen, J., Pablo, J.J. de, & Dumesic, J.A. Equilibrated adsorption of CO on silica-supported Pt catalysts. United States. doi:10.1021/jp993833o.
Podkolzin, S.G., Shen, J., Pablo, J.J. de, and Dumesic, J.A. Thu . "Equilibrated adsorption of CO on silica-supported Pt catalysts". United States. doi:10.1021/jp993833o.
@article{osti_20050846,
title = {Equilibrated adsorption of CO on silica-supported Pt catalysts},
author = {Podkolzin, S.G. and Shen, J. and Pablo, J.J. de and Dumesic, J.A.},
abstractNote = {Microcalorimetric and infrared spectroscopic studies of CO adsorption on Pt/SiO{sub 2} were conducted at temperatures from 298 to 673 K. The adsorption of CO on silica-supported Pt is equilibrated at 673 K, and the microcalorimetric and spectroscopic results obtained at this elevated temperature are in agreement with results reported for Pt(111) at 300 K. The heat of CO adsorption decreases with coverage from the initial value of 190--180 kJ/mol to 75 kJ/mol at the saturation CO coverage of 0.7 ML. In addition, the IR band for CO adsorbed on atop sites shifts to higher wave numbers, and the ratio of integral absorbances of bridge-bonded and atop-bonded species changes with CO coverage. At temperatures lower than 673 K, the adsorption of CO on Pt/SiO{sub 2} is not equilibrated, and the microcalorimetric and IR spectroscopic data are essentially independent of the apparent CO coverage. A Monte Carlo simulation model was used to consolidate data for CO adsorption on Pt/SiO{sub 2} and Pt(111). The simulation was based on a set of parameters describing the energetics for the formation of atop- and bridge-bonded CO species on a clean surface and lateral pairwise interactions between these species on a two-dimensional hexagonal lattice representing a Pt(111) surface.},
doi = {10.1021/jp993833o},
journal = {Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical},
issn = {1089-5647},
number = 17,
volume = 104,
place = {United States},
year = {2000},
month = {5}
}