@article { ISI:000227565800022,
	title = {Oxidative dehydrogenation of ethylbenzene over vanadia-alumina catalysts in the presence of nitrous oxide: structure-activity relationship},
	journal = {Journal of Catalysis},
	volume = {230},
	number = {2},
	year = {2005},
	month = {MAR},
	pages = {484-492},
	publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE},
	type = {Article},
	address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA},
	abstract = {<p>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.</p>},
	keywords = {absorption edge energy, Alumina, ethylbenzene, Nitrous oxide, oxidative dehydrogenation, polyvanadates, styrene, vanadia},
	issn = {0021-9517},
	doi = {10.1016/j.jcat.2005.01.010},
	author = {Shiju, N. R. and Anilkumar, Mettu and Mirajkar, Subhash P. and Gopinath, Chinnakonda S. and Rao, B. S. and Satyanarayana, C. V.}
}
