Synthesis and spectroscopic studies of vanadium-containing molecular sieves
- Universite Laval, Quebec (Canada); and others
New vanadium containing large pore and mesoporous molecular sieves with ZSM-12 and MCM-41 structures were synthesized and characterized by variety of chemico-physical methods. All samples showed promising properties in the oxidation of organic substrates by hydrogen peroxide. Based on EPR and multinuclear NMR data a possible mechanism of vanadium incorporation into the lattice of the molecular sieves is proposed. It is shown, that part of vanadium incorporates the lattice during the hydrothermal synthesis. Incorporation of the other part takes place during high temperature calcination through interaction with hydroxyl groups at defect sites. The local coordination of vanadium in these materials has been examined by EPPI and {sup 51}V NMR. In calcined samples, vanadium was coordinated to four oxygen atoms in tetrahedral symmetry and could be easily converted from V(5+) to V(4+) and vice versa. Possible models of the local environment of vanadium will be proposed, and catalytic properties presented.
- OSTI ID:
- 126786
- Report Number(s):
- CONF-950402--
- Country of Publication:
- United States
- Language:
- English
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