A surface and catalytic study of heterogenised Os3(CO) 12 species in MCM-41 structures
Immobilised Os species prepared via chemical vapour deposition (CVD) of Os3(CO)12 onto MCM-41 are active and selective catalysts for the dihydroxylation of trans-stilbene in acetone and water, using N-methylmorpholine N-oxide as the oxidant. A detailed temperature programmed decomposition study of t...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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2003
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| _version_ | 1797087124749549568 |
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| author | Caps, V Paraskevas, I Tsang, S |
| author_facet | Caps, V Paraskevas, I Tsang, S |
| author_sort | Caps, V |
| collection | OXFORD |
| description | Immobilised Os species prepared via chemical vapour deposition (CVD) of Os3(CO)12 onto MCM-41 are active and selective catalysts for the dihydroxylation of trans-stilbene in acetone and water, using N-methylmorpholine N-oxide as the oxidant. A detailed temperature programmed decomposition study of the solids enables to identify the active sites as Osx(CO)y surface species. The initial loading of the MCM-41 with the trinuclear precursor, as well as the temperature of the post-synthesis oxidising treatment, are found to have a significant impact on the structure/geometry of the resulting surface species, and thus their catalytic properties. We show how it is also affected by the confined environment of the MCM-41 mesopores and especially the curvature of the 30 Å diameter channels. Finally, a careful study of the catalytic properties of the materials together with a study of the reactivity of the reaction products under similar conditions enable to suggest a mechanism involving the reaction of the oxidant with the osmium carbonyl surface species to form the catalytically active Os-oxo sites, and the formation of an osmoate-type species (through adsorption of the alkene onto the Os-oxo site) which subsequently reacts with the solvent to produce the diol. © 2003 Elsevier B.V. All rights reserved. |
| first_indexed | 2024-03-07T02:31:40Z |
| format | Journal article |
| id | oxford-uuid:a770b73f-9370-4e8f-8f3d-2a7864cd2c75 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:31:40Z |
| publishDate | 2003 |
| record_format | dspace |
| spelling | oxford-uuid:a770b73f-9370-4e8f-8f3d-2a7864cd2c752022-03-27T02:54:39ZA surface and catalytic study of heterogenised Os3(CO) 12 species in MCM-41 structuresJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a770b73f-9370-4e8f-8f3d-2a7864cd2c75EnglishSymplectic Elements at Oxford2003Caps, VParaskevas, ITsang, SImmobilised Os species prepared via chemical vapour deposition (CVD) of Os3(CO)12 onto MCM-41 are active and selective catalysts for the dihydroxylation of trans-stilbene in acetone and water, using N-methylmorpholine N-oxide as the oxidant. A detailed temperature programmed decomposition study of the solids enables to identify the active sites as Osx(CO)y surface species. The initial loading of the MCM-41 with the trinuclear precursor, as well as the temperature of the post-synthesis oxidising treatment, are found to have a significant impact on the structure/geometry of the resulting surface species, and thus their catalytic properties. We show how it is also affected by the confined environment of the MCM-41 mesopores and especially the curvature of the 30 Å diameter channels. Finally, a careful study of the catalytic properties of the materials together with a study of the reactivity of the reaction products under similar conditions enable to suggest a mechanism involving the reaction of the oxidant with the osmium carbonyl surface species to form the catalytically active Os-oxo sites, and the formation of an osmoate-type species (through adsorption of the alkene onto the Os-oxo site) which subsequently reacts with the solvent to produce the diol. © 2003 Elsevier B.V. All rights reserved. |
| spellingShingle | Caps, V Paraskevas, I Tsang, S A surface and catalytic study of heterogenised Os3(CO) 12 species in MCM-41 structures |
| title | A surface and catalytic study of heterogenised Os3(CO) 12 species in MCM-41 structures |
| title_full | A surface and catalytic study of heterogenised Os3(CO) 12 species in MCM-41 structures |
| title_fullStr | A surface and catalytic study of heterogenised Os3(CO) 12 species in MCM-41 structures |
| title_full_unstemmed | A surface and catalytic study of heterogenised Os3(CO) 12 species in MCM-41 structures |
| title_short | A surface and catalytic study of heterogenised Os3(CO) 12 species in MCM-41 structures |
| title_sort | surface and catalytic study of heterogenised os3 co 12 species in mcm 41 structures |
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