02623nas a2200301 4500008004100000022001400041245014300055210006900198260009500267300001200362490000800374520152800382653002701910653001201937653001701949653001801966653003001984653001802014653001202032653001202044100001802056700002102074700002602095700003002121700001602151700002602167856012802193 2005 eng d a0021-951700aOxidative dehydrogenation of ethylbenzene over vanadia-alumina catalysts in the presence of nitrous oxide: structure-activity relationship0 aOxidative dehydrogenation of ethylbenzene over vanadiaalumina ca a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcMAR a484-4920 v2303 a

A series of vanadia-alumina catalysts with different vanadia contents were prepared by a wet impregnation method. The influence of the local structure of vanadia in these catalysts on the oxidative dehydrogenation of ethylbenzene with nitrous oxide was investigated. The use of N2O as a co-feed remarkably enhanced the styrene yield compared with the use of N-2. Characterization of these vanadia catalysts by XRD, FTIR, UV-vis, TPR, XPS, and V-51 NMR techniques suggests that the nature of the VOx species depends on the vanadia loading: the predominant species are monomeric vanadia at lower loadings, two-dimensional polyvanadates at intermediate loadings, and bulk-like V2O5 and AlVO4 at higher loadings. The rate of oxidative dehydrogenation (ODH) of ethylbenzene per vanadium atom increases with vanadia loading and reaches a maximum at 10 wt%, the loading at which the surface predominantly contains polyvanadate species. The observed variation in the selectivity of products with vanadium loading indicates that the monomeric V5+ species favors dehydrogenation, whereas bulk-like V2O5 preferentially participates in the dealkylation of ethylbenzene. The vanadium species remains at a higher oxidation state in the presence of N2O, leading to a higher styrene yield. than in a N-2 atmosphere. The ODH turnover rates increased with decreasing energy of the absorption edge in the UV-vis spectrum, at low VOx coverages of less than one monolayer on the Al2O3 surface. (c) 2005 Elsevier Inc. All rights reserved.

10aabsorption edge energy10aAlumina10aethylbenzene10aNitrous oxide10aoxidative dehydrogenation10apolyvanadates10astyrene10avanadia1 aShiju, N., R.1 aAnilkumar, Mettu1 aMirajkar, Subhash, P.1 aGopinath, Chinnakonda, S.1 aRao, B., S.1 aSatyanarayana, C., V. uhttps://library.ncl.res.in/content/oxidative-dehydrogenation-ethylbenzene-over-vanadia-alumina-catalysts-presence-nitrous-002031nas a2200241 4500008004100000022001400041245016300055210006900218260007300287300001200360490000800372520113200380653001101512653001701523653000801540653001701548653001401565100002601579700001601605700001901621700001801640856013101658 2006 eng d a1381-116900aCobalt-containing hexagonal mesoporous molecular sieves (Co-HMS): Synthesis, characterization and catalytic activity in the oxidation reaction of ethylbenzene0 aCobaltcontaining hexagonal mesoporous molecular sieves CoHMS Syn aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG a123-1300 v2553 a

Cobalt-containing hexagonal mesoporous materials (Co-HMS and Co/HMS) with different cobalt content were synthesized for the first time by direct hydrothermal and post-synthesis (grafting) method. The materials were characterized in detail by X-ray diffraction, BET surface area, N-2 sorption isotherms, SEM, TEM, UV-vis and XPS techniques. Powder X-ray diffraction pattern, N2 adsorption-desorption analysis and TEM analysis show the presence of hexagonal mesoporous structure, having Type W isotherms and reveals the typical wormhole-like morphology. Spectroscopic techniques like UV-vis and XPS reveal cobalt in +2 oxidation state and tetrahedrally coordinated. Liquid phase oxidation of ethylbenzene using TBHP (70 wt%) as an oxidant shows that the catalysts are highly active, under solvent free conditions as well as under lower cobalt concentrations. Leaching studies performed by hot filtration experiments show that the cobalt catalysts prepared by hydrothermal methods are stable, while the grafted catalysts show the leaching of cobalt under the reaction conditions. (c) 2006 Elsevier B.V. All rights reserved.

10aCo-HMS10aethylbenzene10aHMS10ahydrothermal10aOxidation1 aBhoware, Shrikant, S.1 aShylesh, S.1 aKamble, K., R.1 aSingh, A., P. uhttps://library.ncl.res.in/content/cobalt-containing-hexagonal-mesoporous-molecular-sieves-co-hms-synthesis-characterization-001758nas a2200229 4500008004100000022001400041245007200055210006900127260007300196300001200269490000700281520100100288653001301289653001901302653002301321653001701344653001901361100001801380700001201398700002201410856009601432 2009 eng d a1003-995300aDisproportionation of ethylbenzene in the presence of C-8 aromatics0 aDisproportionation of ethylbenzene in the presence of C8 aromati aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a369-3740 v183 a

The selective synthesis of p-diethylbenzene (p-DEB) by disproportionation of ethylbenzene (EB) in the presence of aromatics like m- and p-xylene isomers has been studied over a pore size regulated HZSM-5 catalyst. The industrial feed having different compositions of ethylbenzene and xylene isomers was used for the experimentation. Hence, they were expected to hinder the movement of reactant molecules both on the external surface and within the zeolite channels. It was observed that irrespective of the different feed compositions the concentration of the xylene isomers was intact in the product. There is no other byproducts formation like para-ethylmethyl benzene. The effects of varying the concentration of aromatic compounds in the feed on ethylbenzene conversion and product distribution over the parent and modified H-ZSM-5 catalyst have been discussed. Ethylbenzene disproportionation reaction follows the pseudo first order reaction with an activation energy of 8.6 kcal/mol.

10aCatalyst10adiethylbenzene10adisproportionation10aethylbenzene10axylene isomers1 aSharnappa, N.1 aPai, S.1 aBokade, Vijay, V. uhttps://library.ncl.res.in/content/disproportionation-ethylbenzene-presence-c-8-aromatics-002028nas a2200217 4500008004100000022001400041245012300055210006900178260000800247520122800255653001701483653001701500653002801517653002301545653002401568100002601592700001801618700002001636700002201656856013201678 2021 eng d a1011-372X00aReview on selective production of acetophenone from oxidation of ethylbenzene over heterogeneous catalysts in a decade0 aReview on selective production of acetophenone from oxidation of cJAN3 a

The consumption of acetophenone (AP) is increasing worldwide because of its applications in products such as alcohol, aldehydes, resins, esters, fragrances, and pharmaceuticals. AP is manufactured via several methods like decomposition of cumene hydroperoxide, Hock process, and Friedel-Crafts acylation reaction using homogeneous catalysts with solvent and oxidant. However, it causes several environmental problems that deteriorate the production of AP with these methods. Oxidation of ethylbenzene (EB) is one of the promising methods to synthesize AP in liquid and vapor phases reaction using heterogeneous catalysts, which plays a vital role for selective production of AP. In this review, numerous heterogeneous catalysts are discussed including transition metal nanoparticles, transition metal complexes, and metal free catalysts (carbon nanotubes) used in last 10 years for oxidation of EB. Additionally, catalyst activity along with reaction parameters and its effect, mechanisms, and kinetics study are summarized in this article. The future scope of this reaction is also highlighted. Moreover, this work identifies best catalysts for bulk production of AP with high yield to satisfy global requirement.

10aacetophenone10aethylbenzene10aHeterogeneous catalysts10aOxidation reaction10areaction mechanisms1 aNandanwar, Sachin, U.1 aRathod, Simmy1 aBansal, Videsha1 aBokade, Vijay, V. uhttps://library.ncl.res.in/content/review-selective-production-acetophenone-oxidation-ethylbenzene-over-heterogeneous-catalysts