Heteropolyacid catalysts for hydroisomerization of n-hexane: Effects of alkali salt modification

Citation
N. Essayem et al., Heteropolyacid catalysts for hydroisomerization of n-hexane: Effects of alkali salt modification, J CATALYSIS, 204(1), 2001, pp. 157-162
Citations number
14
Categorie Soggetti
Physical Chemistry/Chemical Physics","Chemical Engineering
Journal title
JOURNAL OF CATALYSIS
ISSN journal
00219517 → ACNP
Volume
204
Issue
1
Year of publication
2001
Pages
157 - 162
Database
ISI
SICI code
0021-9517(20011115)204:1<157:HCFHON>2.0.ZU;2-C
Abstract
12-Tungstophosphoric acid, H3PW12O40, and a series of its acid alkali salts associated with silica-supported platinum have been used as catalysts in t he hydroisomerization of n-hexane and compared with platinum-supported, app ropriately dealuminated mordenite. High selectivity toward isomerization wa s observed with both the heteropolyacid (HPA)-type catalysts and the morden ite at elevated conversions. The acid sites of the heteropolyacids/salts ex hibited an efficiency higher than that of mordenite, in line with the highe r acid strength of the former sites. Yet, despite their higher acid strengt h, heteropolyacids/salts showed a lower selectivity toward dimethylbutanes than mordenite. In addition, heteropolyacids, though more active than morde nite at low temperature, appeared to be only poor monofunctional isomerizat ion catalysts. (C) 2001 Academic Press.