Effect of the deposition temperature on the chemical vapour deposition of tetraethoxysilane on ZSM-5

✍ Scribed by Heiko Manstein; Klaus P. Möller; Walter Böhringer; Cyril T. O'Connor

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 271 KB
• Volume: 51
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(01)00466-8

✦ Synopsis

The effect of deposition temperature during the chemical vapour deposition of tetraethoxysilane (TEOS) on zeolite H-ZSM-5 was studied over the temperature range from 50 to 400 °C. Cracking of 1,3,5-triisopropylbenzene and disproportionation of toluene (T-DP) showed the extent of modification by the silica deposition. Ethanol dehydration at elevated temperatures as subsequent step to TEOS deposition leads to non-uniform deposition and reduced catalyst activity. From both shape-selectivity improvements and catalytic activity it is seen, that low deposition temperatures and frequent modification cycles are the preferred conditions for obtaining catalysts with improved shape selectivity at preserved conversion levels.