<?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%">Pai, Shivanand</style></author><author><style face="normal" font="default" size="100%">Gupta, Upendranath</style></author><author><style face="normal" font="default" size="100%">Chilukuri, Satyanarayana V.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Butylation of toluene: influence of zeolite structure and acidity on 4-tert-butyltoluene selectivity</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Molecular Catalysis A-Chemical</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">4-t-butyltoluene</style></keyword><keyword><style  face="normal" font="default" size="100%">Acidity</style></keyword><keyword><style  face="normal" font="default" size="100%">butylation</style></keyword><keyword><style  face="normal" font="default" size="100%">large pore zeolites</style></keyword><keyword><style  face="normal" font="default" size="100%">Toluene</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</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</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%">265</style></volume><pages><style face="normal" font="default" size="100%">109-116</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Vapour phase alkylation of toluene with tert-butyl alcohol was studied over the large pore zeolites H beta, HY and HMCM-22. The influence of the acidity, reaction temperature, run duration, feed rate (WHSV) and molar ratio of the reactants on conversion of toluene and selectivity for 4-tertbutyl toluene was studied. Among the isomers formed during the reaction, the para-isomer was the predominant one, followed by the meta-isomer, while no ortho-isomer was found in the products due to steric factors. 4-tert-Butyl toluene selectivity decreases at higher temperatures, while going through a maximum in the 413-433 K temperature range. Zeolite HY with a high silica to alumina ratio (SiO2/Al2O3 = 80), that has strong acidity, but lower acid site density, possesses high activity for toluene conversion, high alkylation selectivity and also high para-selectivity. The improved para-selectivity of high silica HY zeolite is attributed to the low isomerization activity that results in the suppression of the secondary isomerization of 4-tert-butyl toluene. Both alkylation and selectivity are higher with feed mixtures containing a lower fraction of tert-butyl alcohol. (c) 2006 Elsevier B.V. All rights reserved.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">1-2</style></issue><work-type><style face="normal" font="default" size="100%">Article</style></work-type><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">3.958</style></custom4></record></records></xml>