INOR 840 |
| Cr(IV) substituted silicalite-1 was generated by the reduction of Cr(VI)-silicalite-2 in a CO atmosphere. The reduction of the Cr(VI) site occurs with removal of a terminal oxygen from the Cr. This results in non-intuitive structural changes in the silicalite-2 lattice, specifically a decrease in the unit cell volume. As generated, the Cr(IV) sites are both isostructural and isovalent with the Ti(IV) sites in TS-1 and TS-2. These materials show a high degree of catalytic activity towards the oxidation of phenol to catechol and hydroquinone using hydrogen peroxide. In the initial stages of the reaction the activity is significantly greater than TS-1, however, over time the catalyst deactivates. The reaction enhanced rate is attributed to a reduction in the activation energy for hydrogen peroxide coordination brought on by crystal field contributions to the activation energy |
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Inorganic Catalysts
1:30 PM-5:30 PM, Wednesday, 16 March 2005 Convention Center -- Room 6F, Oral
Division of Inorganic Chemistry |