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Support‐dependent activity of noble metal substituted oxide catalysts for the water gas shift reaction
Author(s) -
Deshpande Parag A.,
Madras Giridhar
Publication year - 2010
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.12177
Subject(s) - catalysis , water gas shift reaction , oxide , chemistry , adsorption , noble metal , dissociation (chemistry) , reaction mechanism , metal , inorganic chemistry , nanocrystalline material , reaction rate , ion , photochemistry , organic chemistry , crystallography
The water gas shift reaction was carried out over noble metal ion substituted nanocrystalline oxide catalysts with different supports. Spectroscopic studies of the catalysts before and after the reaction showed different surface phenomena occurring over the catalysts. Reaction mechanisms were proposed based upon the surface processes and intermediates formed. The dual site mechanism utilizing the oxide ion vacancies for water dissociation and metal ions for CO adsorption was proposed to describe the kinetics of the reaction over the reducible oxides like CeO 2 . A mechanism based on the interaction of adsorbed CO and the hydroxyl group was proposed for the reaction over ZrO 2 . A hybrid mechanism based on oxide ion vacancies and surface hydroxyl groups was proposed for the reaction over TiO 2 . The deactivation of the catalysts was also found to be support dependent. Kinetic models for both activation and deactivation were proposed. © 2010 American Institute of Chemical Engineers AIChE J, 2010