skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Solid electrolyte potentiometric study of La(Sr)MnO{sub 3} catalyst during carbon monoxide oxidation

Abstract

The catalytic behaviour of the perovskite oxide La{sub 0.5}Sr{sub 0.5}MnO{sub 3-{delta}} was investigated during carbon monoxide oxidation at 500-550{degrees}C. The technique of solid electrolyte potentiometry was employed to monitor the oxygen activity of the solid catalyst under reaction conditions. At 550{degrees}C, the reaction rate was found to be a function of the gas phase oxygen (or carbon monoxide) partial pressure and the catalysts oxygen activity. At 500{degrees}C, the rate tended to depend only on the gas phase composition and not on the catalyst state. The results suggested that the reaction mechanism changes from an ionic redox model (550{degrees}C), where the reoxidation of the reduced sites occurs by lattice oxygen, to a Mars-van Krevelen redox model (500{degrees}C), where the reoxidation occurs by gas phase oxygen. The hysteresis at 550{degrees}C was attributed to diffusional limitations appearing during either the reoxidation of the reduced sites or the reoxidation of the oxide bulk. The change in the reaction mechanism in going from 500 to 550{degrees}C was considered to be the result of an increase in the mobility of lattice oxygen, in agreement with the oxygen temperature programmed desorption profile of the catalyst. 41 refs., 11 figs.

Authors:
;  [1]
  1. Imperial College of Science, Technology and Medicine, London (United Kingdom)
Publication Date:
OSTI Identifier:
525937
Resource Type:
Journal Article
Journal Name:
Journal of Catalysis
Additional Journal Information:
Journal Volume: 152; Journal Issue: 1; Other Information: PBD: Mar 1995
Country of Publication:
United States
Language:
English
Subject:
33 ADVANCED PROPULSION SYSTEMS; 01 COAL, LIGNITE, AND PEAT; 20 FOSSIL-FUELED POWER PLANTS; 40 CHEMISTRY; CARBON MONOXIDE; OXIDATION; LANTHANUM OXIDES; CATALYTIC EFFECTS; STRONTIUM OXIDES; MANGANESE OXIDES; CATALYSTS; SOLID ELECTROLYTES; POTENTIOMETRY; STOICHIOMETRY; CHEMICAL REACTION KINETICS; HETEROGENEOUS CATALYSIS

Citation Formats

Petrolekas, P D, and Metcalfe, I S. Solid electrolyte potentiometric study of La(Sr)MnO{sub 3} catalyst during carbon monoxide oxidation. United States: N. p., 1995. Web. doi:10.1006/jcat.1995.1069.
Petrolekas, P D, & Metcalfe, I S. Solid electrolyte potentiometric study of La(Sr)MnO{sub 3} catalyst during carbon monoxide oxidation. United States. https://doi.org/10.1006/jcat.1995.1069
Petrolekas, P D, and Metcalfe, I S. 1995. "Solid electrolyte potentiometric study of La(Sr)MnO{sub 3} catalyst during carbon monoxide oxidation". United States. https://doi.org/10.1006/jcat.1995.1069.
@article{osti_525937,
title = {Solid electrolyte potentiometric study of La(Sr)MnO{sub 3} catalyst during carbon monoxide oxidation},
author = {Petrolekas, P D and Metcalfe, I S},
abstractNote = {The catalytic behaviour of the perovskite oxide La{sub 0.5}Sr{sub 0.5}MnO{sub 3-{delta}} was investigated during carbon monoxide oxidation at 500-550{degrees}C. The technique of solid electrolyte potentiometry was employed to monitor the oxygen activity of the solid catalyst under reaction conditions. At 550{degrees}C, the reaction rate was found to be a function of the gas phase oxygen (or carbon monoxide) partial pressure and the catalysts oxygen activity. At 500{degrees}C, the rate tended to depend only on the gas phase composition and not on the catalyst state. The results suggested that the reaction mechanism changes from an ionic redox model (550{degrees}C), where the reoxidation of the reduced sites occurs by lattice oxygen, to a Mars-van Krevelen redox model (500{degrees}C), where the reoxidation occurs by gas phase oxygen. The hysteresis at 550{degrees}C was attributed to diffusional limitations appearing during either the reoxidation of the reduced sites or the reoxidation of the oxide bulk. The change in the reaction mechanism in going from 500 to 550{degrees}C was considered to be the result of an increase in the mobility of lattice oxygen, in agreement with the oxygen temperature programmed desorption profile of the catalyst. 41 refs., 11 figs.},
doi = {10.1006/jcat.1995.1069},
url = {https://www.osti.gov/biblio/525937}, journal = {Journal of Catalysis},
number = 1,
volume = 152,
place = {United States},
year = {1995},
month = {3}
}