02769nas a2200301   4500008004100000022001400041245007700055210006900132260007300201300001200274490000800286520177700294653001802071653001302089653001302102653002402115653001502139100002802154700002402182700002402206700001902230700001902249700002302268700002402291700002402315700001802339856011002357       2009                        eng d  a1381-116900aAcetalization of glycerol using mesoporous MoO3/SiO2 solid acid catalyst0 aAcetalization of glycerol using mesoporous MoO3SiO2 solid acid c  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP  a150-1580 v3103 a<p>Acetalization of glycerol with various aldehydes has been carried out using mesoporous MoO3/SiO2 as a solid acid catalyst. A series of MoO3/SiO2 catalysts with varying MoO3 loadings(1-20 mol%) were prepared by sol-gel technique using ethyl silicate-40 and ammonium heptamolybdate as silica and molybdenum source respectively. The sol-gel derived samples were calcined at 500 degrees C and characterized using various physicochemical characterization techniques. The XRD of the calcined samples showed the formation of amorphous phase up to 10 mol% MoO3 loading and at higher loading of crystalline alpha-MoO3 on amorphous silica support. TEM analyses of the materials showed the uniform distribution of MoO3 nanoparticles on amorphous silica support. Raman spectroscopy showed the formation of silicomolybdic acid at low Mo loading and a mixture of alpha-MoO3 and polymolybdate species at high Mo loadings. Moreover the Raman spectra of intermediate loading samples also suggest the presence of beta-MoO3. Acetalization of glycerol with benzaldehyde was carried out using series of MoO3/SiO2 catalysts with varying MoO3 loadings (1-20 mol%). Among the series, MoO3/SiO2 With 20 mol% MoO3 loadings was found to be the most active catalyst in acetalization under mild conditions. Maximum conversion of benzaldehyde (72%) was obtained in 8 h at 100 degrees C with 60% selectivity for the six-membered acetal using 20% MoO3/SiO2. Interestingly with substituted benzaldehydes under same reaction conditions the conversion of aldehydes decreased with increase in selectivity for six-membered acetals. These results indicate the potential of this catalyst for the acetalization of glycerol for an environmentally benign process. (C) 2009 Elsevier B.V. All rights reserved.</p>10aAcetalization10aAldehyde10aGlycerol10aSilicomolybdic acid10asolid acid1 aUmbarkar, Shubhangi, B.1 aKotbagi, Trupti, V.1 aBiradar, Ankush, V.1 aPasricha, Renu1 aChanale, Jyoti1 aDongare, Mohan, K.1 aMamede, Anne-Sophie1 aLancelot, Christine1 aPayen, Edmond  uhttps://library.ncl.res.in/content/acetalization-glycerol-using-mesoporous-moo3sio2-solid-acid-catalyst-0