01559nas a2200241   4500008004100000022001400041245013200055210006900187260007300256300001200329490000700341520067600348653002001024653001401044653002201058653001301080653002501093100002101118700002301139700001401162700001701176856012401193       2010                        eng d  a1566-736700aStructure-activity studies of dodecatungstophosphoric acid impregnated bentonite clay catalyst in hydroxyalkylation of p-cresol0 aStructureactivity studies of dodecatungstophosphoric acid impreg  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a942-9450 v113 a<p>Bentonite clay impregnated with dodecatungstophosphoric acid (20% DTP/BNT) showed an excellent activity, selectivity and stability [95% product yield with 94% selectivity to 2, 2'-methylenebis (4-methylphenol), DAM] for the hydroxyalkylation of p-cresol with formaldehyde at 353 K and for a mole ratio of 5. Ammonia-TPD results showed that an increase in total concentration of acid sites from 4.9 of parent bentonite to 11.6 micromoles per surface area NH(3) (mu molS(-1) NH(3)) of 20% DTP/BNT was due to a strong interaction of protons of bulk DTP with surface hydroxyl groups of BNT as evidenced by (31)P NMR studies. (C) 2010 Elsevier B.V. All rights reserved.</p>10a(31)P CPMAS NMR10aBentonite10aHydroxyalkylation10ap-Cresol10asurface modification1 aGarade, Ajit, C.1 aKshirsagar, V., S.1 aJha, Ajay1 aRode, C., V.  uhttps://library.ncl.res.in/content/structure-activity-studies-dodecatungstophosphoric-acid-impregnated-bentonite-clay-0