The transformation of ethanol was carried out over vanadium silicate molecular sieves with MEL topology (VS-2) with different Si/V atomic ratios in the temperature range 523-623 K. The reaction was performed in a fixed-bed down-flow reactor at atmospheric pressure. Acetaldehyde, diethyl ether, and e
Catalytic hydroxylation of phenol over a vanadium silicate molecular sieve with MEL structure
β Scribed by P.R. Hari Prasad Rao; A.V. Ramaswamy
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 514 KB
- Volume
- 93
- Category
- Article
- ISSN
- 0926-860X
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β¦ Synopsis
Vanadium silicate molecular sieves with MEL structure (VS-2) are found to be active in the hydroxylation of phenol with hydrogen peroxide, a reaction which is commercially practiced over titanium silicalite (TS-1 and TS-2) catalysts. Among various reaction parameters, the influence of the solvent on the conversion and product selectivity appears to be different from that reported on titanium silicalites. In methanol, for example, no hydroxylation takes place. In water, the phenol conversion as well as the H,Oa selectivity follows the order, T&l> TS-2 > VS-2. Only those vanadium ions which are in the lattice positions appear to catalyse this reaction.
π SIMILAR VOLUMES
Tin-containing, medium pore molecular sieves (Si/Sn ratios above 40) with MEL structure have been synthesized hydrothermally and characterized by a variety of techniques. Changes in unit cell volume (XRD) account for about 20% of Sn 4 + ions in possible tetrahedral positions, l l9Sn MAS-NMR spectra,