Error message

Notice: Undefined index: webform in custom_search_form_alter() (line 291 of /var/www/library/sites/all/modules/custom_search/custom_search.module).

Heteropoly acid supported on titania as solid acid catalyst in alkylation of p-cresol with tert-butanol

TitleHeteropoly acid supported on titania as solid acid catalyst in alkylation of p-cresol with tert-butanol
Publication TypeJournal Article
Year of Publication2006
AuthorsKumbar, SM, Shanbhag, GV, Lefebvre, F, Halligudi, SB
JournalJournal of Molecular Catalysis A-Chemical
Volume256
Issue2-3
Pagination324-334
Date PublishedAUG
Type of ArticleArticle
ISSN1381-1169
Keywords2, 2-tert-butyl-p-cresol, 6-di-tert-butyl-p-cresol, Alkylation, heteropoly acid, p-Cresol, tert-butanol, titania
Abstract

Butylation of p-cresol with tert-butanol was investigated on titania modified with 12-tungstophosphoric acid (TPA/TiO2) catalyst under vapor phase conditions. Catalysts with different TPA loadings (10-25 wt.%) and calcination temperatures (650-750 degrees C) were prepared by suspending titanium hydroxide in methanol solution of TPA followed by drying and calcination. These catalysts were characterized by surface area, XRD, P-31 MAS NMR, XPS, NH3-TPD, and FTIR pyridine adsorption. XRD results indicated that the presence of TPA retarded the crystallization of titania and stabilized TiO2 in anatase phase. P-31 MAS NMR indicated the presence of TPA in various forms (dispersed, highly fragmented and Keggin intact). These catalysts showed both Bronsted and Lewis acidity, and 20% TPA on TiO2 calcined at 700 degrees C (from here after words 20% TT 700) had the highest Bronsted as well as total acidity. Further, the catalytic activities were examined in tert-butylation of p-cresol with tent-butanol. The catalytic activity depended on TPA coverage, and the highest activity corresponded to the monolayer of TPA on titania. The most active catalyst 20% TT-700 gave 82% conversion of p-cresol and 89.5% selectivity towards 2-tert-butyl cresol (TBC), 2,6-di-tert-butyl cresol (DTBC) 7.5% and cresol-tert-butyl ether (CTBE) 3% under optimized conditions. The activity was always higher than that of WO3/ZrO2, sulfated zirconia (SZ), USY, H-beta zeolites and montmorillonite K-10 (K-10mont) under similar conditions. (c) 2006 Elsevier B.V. All rights reserved.

DOI10.1016/j.molcata.2006.05.024
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

3.958

Divison category: 
Catalysis and Inorganic Chemistry