<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rode, C. V.</style></author><author><style face="normal" font="default" size="100%">Garade, Ajit C.</style></author><author><style face="normal" font="default" size="100%">Chikate, Rajeev C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Solid acid catalysts: modification of acid sites and effect on activity and selectivity tuning in various reactions</style></title><secondary-title><style face="normal" font="default" size="100%">Catalysis Surveys from Asia</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acidity tuning</style></keyword><keyword><style  face="normal" font="default" size="100%">Catalytic cleavage</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydroxyalkylation</style></keyword><keyword><style  face="normal" font="default" size="100%">Intramolecular rearrangement</style></keyword><keyword><style  face="normal" font="default" size="100%">solid acid catalysts</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">SEP</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">3</style></number><publisher><style face="normal" font="default" size="100%">SPRINGER/PLENUM PUBLISHERS</style></publisher><pub-location><style face="normal" font="default" size="100%">233 SPRING ST, NEW YORK, NY 10013 USA</style></pub-location><volume><style face="normal" font="default" size="100%">13</style></volume><pages><style face="normal" font="default" size="100%">205-220</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;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.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">2.432</style></custom4></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Garade, Ajit C.</style></author><author><style face="normal" font="default" size="100%">Kshirsagar, V. S.</style></author><author><style face="normal" font="default" size="100%">Mane, R. B.</style></author><author><style face="normal" font="default" size="100%">Ghalwadkar, Ajay A.</style></author><author><style face="normal" font="default" size="100%">Joshi, U. D.</style></author><author><style face="normal" font="default" size="100%">Rode, C. V.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Acidity tuning of montmorillonite K10 by impregnation with dodecatungstophosphoric acid and hydroxyalkylation of phenol</style></title><secondary-title><style face="normal" font="default" size="100%">Applied Clay Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acidity tuning</style></keyword><keyword><style  face="normal" font="default" size="100%">Dodecatungstophosphoric acid/Montmorillonite K10</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydroxyalkylation</style></keyword><keyword><style  face="normal" font="default" size="100%">Impregnation</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature programmed desorption</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">MAR</style></date></pub-dates></dates><number><style face="normal" font="default" size="100%">1-2, SI</style></number><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE BV</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">48</style></volume><pages><style face="normal" font="default" size="100%">164-170</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Acidity tuning of montmorillonite K10 (mont K10) was achieved by impregnating with dodecatungstophosphoric acid (DTP). The effect on the hydroxyalkylation of phenol was studied at 353 K with phenol to formaldehyde molar ratio of 5. The nature and strength of acid sites were determined by NH(3)-TPD measurement while the distribution of Brensted and Lewis acid sites expressed as B/L ratio, was determined by pyridine IR technique. Among various loadings of DTP (5-60%) studied for the hydroxyalkylation of phenol, 20% DTP/mont K10 showed the highest catalyst activity (90% selectivity to bisphenol F with 28% conversion of phenol). Both total concentration of acid sites and the distribution of acid sites in a high temperature region were required for the high bisphenol F selectivity. Our catalyst (20% DTP/Mont K10) could be recycled three times. (C) 2009 Elsevier B.V. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">1-2</style></issue><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">2.303</style></custom4></record></records></xml>