@article { ISI:000263491600023,
	title = {Selective hydroxyalkylation of phenol to bisphenol F over dodecatungstophosphoric acid (DTP) impregnated on fumed silica},
	journal = {Applied Catalysis A-General},
	volume = {354},
	number = {1-2},
	year = {2009},
	month = {FEB},
	pages = {176-182},
	publisher = {ELSEVIER SCIENCE BV},
	address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	abstract = {<p>The catalyst activity of various solid acids, such as fumed Silica (SiO(2)) dodecatungstophosphoric acid (DTP), DTP impregnated on SiO(2), amberlyst-15 and montmorillonite KSF/0, was studied for the hydroxyalkylation of phenol to bisphenol F. A well-dispersed DTP on SiO2 catalyst was prepared by the wet impregnation method. The effect of DTP loading on SiO(2) was also compared with bulk DTP and other solid acid catalysts. 20\% DTP/SiO(2) catalyst gave the highest products yield of 34.2\% and selectivity of 90.1\% to bisphenol F, at 353 K and with a phenol-to-formaldehyde mole ratio of 5:1. Ammonia TPD studies of various catalysts showed that an appropriate combination of both strong and weak acid sites of DTP/SiO(2) Was mainly responsible, rather than only the stronger acidity of bulk DTP, for its highest catalytic activity and selectivity. The effect of various reaction parameters like mole ratio, catalyst concentration, temperature and reaction time on product yield and bisphenol F selectivity was also investigated. The catalyst recycle was established by catalyst activity testing. (C) 2008 Elsevier B.V. All rights reserved.</p>},
	keywords = {Bisphenol F, Hydroxyalkylation, NH(3)-TPD, Reaction pathways, solid acid catalysts},
	issn = {0926-860X},
	doi = {10.1016/j.apcata.2008.11.025},
	author = {Garade, Ajit C. and Kshirsagar, V. S. and Rode, C. V.}
}
@article { ISI:000270338700005,
	title = {Solid acid catalysts: modification of acid sites and effect on activity and selectivity tuning in various reactions},
	journal = {Catalysis Surveys from Asia},
	volume = {13},
	number = {3},
	year = {2009},
	month = {SEP},
	pages = {205-220},
	publisher = {SPRINGER/PLENUM PUBLISHERS},
	address = {233 SPRING ST, NEW YORK, NY 10013 USA},
	abstract = {<p>The effects of acidity and variation in concentration of acid sites of dodecatungstophosphoric acid (DTP), supported DTP and montmorillonite-K catalysts were studied for various organic reactions such as the hydroxyalkylation of phenols to bisphenols, intramolecular rearrangement of benzyl phenyl ether (BPE) to 2-benzyl phenol (2-BP) and selective cleavage of tert-butyldimethylsilyl (TBDMS) ether into the corresponding alcohol. Both dodecatungstophosphoric acid (DTP) impregnated on silica (SiO(2)) and montmorillonite catalysts showed the highest catalyst activity with 90-95\% selectivity to bisphenol for the hydroxyalkylation of phenols to give bisphenol. Temperature Programmed Desorption (TPD) of ammonia and activity results of various catalysts showed that an appropriate combination of both strong and weak acidic sites in the catalyst was highly desirable for high bisphenol selectivity. A 10\% DTP/SiO(2) catalyst was found to be highly selective for the cleavage of TBDMS ether into the corresponding alcohol at room temperature giving a high TON of 9.5 x 10(5) even after the 4th recycle. DTP was also found to be a promising solid acid catalyst for the intramolecular rearrangement of BPE giving 2-BP.</p>},
	keywords = {Acidity tuning, Catalytic cleavage, Hydroxyalkylation, Intramolecular rearrangement, solid acid catalysts},
	issn = {1571-1013},
	doi = {10.1007/s10563-009-9078-4},
	author = {Rode, C. V. and Garade, Ajit C. and Chikate, Rajeev C.}
}
