01922nas a2200229   4500008004100000022001400041245014000055210006900195260007300264300001000337490000800347520104900355653001701404653002201421653002201443653002001465100002201485700001701507700002401524700001801548856012601566       2011                        eng d  a0926-860X00aIn situ encapsulation of Pt nanoparticles in mesoporous silica: synthesis, characterisation and effect of particle size on CO oxidation0 aIn situ encapsulation of Pt nanoparticles in mesoporous silica s  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a91-970 v4033 a<p>Pt nanoparticles of narrow size distribution and average particle size of 4.4 nm are isolated exclusively inside SBA-12 mesoporous silica by a novel in situ method. The interaction of Pt precursor with surfactant-polymer composite micelle is followed by NMR and UV studies. The final Pt incorporated silica material is characterised by XRD, TEM and N(2) adsorption. The mesoporous nature of the silica is found to be intact after Pt incorporation without any pore blockage. CO oxidation activity of this material is compared with that of mesoporous silica incorporating different sizes of Pt viz., 1.8, 3.6 and 8 nm. Activation energies of CO oxidation for all these materials are calculated by a simple differential method based on first principles. A comparison of activation energies and single site yields reveals that these parameters are distinguishably less in catalyst containing 1.8 nm Pt nanoparticles but more or less same in catalysts containing 3.6, 4.4 and 8 nm Pt nanoparticles. (C) 2011 Elsevier B.V. All rights reserved.</p>10aCO oxidation10aIn situ synthesis10aMesoporous silica10aPt nanoparticle1 aPrashar, Atul, K.1 aMayadevi, S.1 aRajamohanan, P., R.1 aDevi, Nandini  uhttps://library.ncl.res.in/content/situ-encapsulation-pt-nanoparticles-mesoporous-silica-synthesis-characterisation-and-001696nas a2200253   4500008004100000022001400041245011300055210006900168260007300237300001000310490000700320520076400327653001001091653003101101653003301132653002101165653002201186653002101208653002801229100002201257700001701279700001801296856012801314       2012                        eng d  a1566-736700aEffect of particle size on selective hydrogenation of cinnamaldehyde by Pt encapsulated in mesoporous silica0 aEffect of particle size on selective hydrogenation of cinnamalde  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a42-460 v283 a<p>Pt nanoparticles of various sizes, viz. 8. 4.9, 3.6 and 1.8 nm were encapsulated in 2D hexagonal mesoporous silica by in-situ synthesis as well as post synthetic modifications so that the final catalyst composition was &lt;= 1 wt.% Pt/SiO2. A kinetic analysis of the effect of particle size on selective hydrogenation of cinnamaldehyde was carried out on these catalysts. It was found that the materials, even at such low loading of Pt, were very active for the hydrogenation and selective for the desired product, cinnamyl alcohol. Among the different particle sizes, selectivity was found to be the highest on 8 nm particles. Kinetic analysis shows that the reaction follows a consecutive reaction pathway. (C) 2012 Elsevier B.V. All rights reserved.</p>10aalpha10abeta-Unsaturated aldehydes10aCinnamaldehyde hydrogenation10aKinetic analysis10aMesoporous silica10aPt nanoparticles10aSelective hydrogenation1 aPrashar, Atul, K.1 aMayadevi, S.1 aDevi, Nandini  uhttps://library.ncl.res.in/content/effect-particle-size-selective-hydrogenation-cinnamaldehyde-pt-encapsulated-mesoporous-0