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          Institute: Fritz-Haber-Institut     Collection: Inorganic Chemistry     Display Documents



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ID: 276537.1, Fritz-Haber-Institut / Inorganic Chemistry
In Situ Spectroscopic Investigation of Activation, Start-Up and Deactivation of Promoted Sulfated Zirconia Catalysts
Authors:Klose, Barbara S.; Jentoft, Friederike C.; Joshi, Pradnya; Trunschke, Annette; Schlögl, Robert; Subbotina, Irina R.; Kazansky, Vladimir B.
Language:English
Research Context:Project 1, Acid-base & redox properties of promoted sulfated zirconia
Date of Publication (YYYY-MM-DD):2006
Title of Journal:Catalysis Today
Volume:116
Start Page:121
End Page:131
Review Status:Peer-review
Audience:Experts Only
Intended Educational Use:No
Abstract / Description:Abstract
Sulfated zirconia (SZ), unpromoted and promoted with 0.5–2.0 wt% Mn or Fe, was investigated by in situ IR and UV–vis spectroscopy during activation at 723–773 K and interaction with n-butane at 298–323 K. During start-up of the catalysts, the isomerization rate increases with the amount of water that is being formed, consistent with an activation of n-butane via oxidative dehydrogenation. Sulfate is the most likely oxidizing agent because activity is also observed for unpromoted SZ and without reduction of Mn. Isomerized species were also found on the surface of Fe-promoted SZ after exposure to n-butane without water formation indicating other yet unknown initiation pathways. During isomerization, Lewis acid sites on Fe-promoted SZ are blocked by water; the valence of Mn decreases only if the catalyst was previously activated in O2. Stable species absorbing at 2820–2840 cm-1 detected on the surface of SZ and Fe-promoted SZ after contact with n-butane at 298 K are tentatively ascribed to alkoxides, which may be side-products or intermediates. These species differ slightly for the two catalysts, reflecting the different structural and electronic properties of the materials.
Free Keywords:IR spectroscopy, UV–vis spectroscopy, diffuse reflectance, in situ, promoted sulfated zirconia, butane isomerization, catalyst deactivation
External Publication Status:published
Document Type:Article
Communicated by:Robert Schlögl
Affiliations:Fritz-Haber-Institut/Inorganic Chemistry/Functional Characterization
Fritz-Haber-Institut/Inorganic Chemistry/Preparation
Fritz-Haber-Institut/Inorganic Chemistry/Inorganic Chemistry
External Affiliations:N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences,
Leninsky Prospect 47, Moscow 117913, Russia
Identifiers:URL:http://www.sciencedirect.com/science?_ob=MImg&_ima... [only for subscriber]
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