Oxidative dehydrogenation of propane over niobia supported vanadium oxide catalysts

Abstract

Oxidative dehydrogenation (ODH) of propane is examined over a series of catalysts, which include Nb,O, supported monolayer VzO, catalysts, bulk vanadia-niobia with different vanadium oxide loadings and prepared by four different methods, VzO, and NbzO,. The intrinsic activity (TOF) of the samples studied indicates that vanadium containing active sites are indispensable for catalytic oxidative dehydrogenation of propane. Variations in the chemical environment of the vanadium ion do not cause significant changes in activity per site and, hence, all samples show similar TOF when the rates are normalised to the concentration of V on the surface. Selectivity to propene on the other hand strongly depends on the nature of the catalyst because readsorption and interaction of propene with the acid sites leads to total oxidation. Optimization of the weak sorption of propane is, therefore, concluded to be the key factor for the design of selective oxidative dehydrogenation catalysts.

Molecular adsorption on V2O3(0001)/Au(111) surfaces

“…The feature at 140 K with first order desorption kinetics is probably due to propane adsorption on vanadyl (V=O) sites, since its considerable intensity rather rules out adsorption on defects. Propane may adsorb on these sites via C-vanadyl interaction and via H bonding between one H atom of a CH 3 group to oxygen of the V 2 O 3 film, as proposed for propane adsorption on technical vanadia catalysts [1][2][3]10,11,[44][45][46][47][48]. The feature at 160 K appearing at low exposure (0.3 L) is attributed to the adsorption of propane on defect sites (such as missing vanadyl oxygen atoms and/or oxygen vacancies in the first layer).…”

Simultaneous thermal cracking and oxidation of propane to propylene and ethylene

“…Since the demand for propylene is increasing day by day, efforts are being made to develop processes for producing propylene from propane, particularly by catalytic oxidative dehydrogenation of propane (Chaar et al, 1988;Sam et al, 1990;Smits et al, 1991Smits et al, , 1995Burch and Crabb, 1993;Corma et al, 1993a,b;Huff and Schmidt, 1994;Gao et al, 1994a,b;Yoon et al, 1994;Eon and Volta, 1994;Bharadwaj and Schmidt, 1995;Blasco et al, 1995;Mamedov and Corberan, 1995;Parmaliana et al, 1996;Watling et al, 1996;Lee et al, 1997). Propylene with high yields has also been obtained by the noncatalytic oxidative dehydrogenation of propane (Burch and Crabb, 1993).…”

The Promotion of Vanadia–Alumina and Vanadia–Titania Catalysts by Surface Molybdenum Oxide for the Propane ODH Reaction

“…Tuning of conversion-selectivity relationship is of primary importance for the development of a desired catalyst that can provide high alkene yield at high alkane conversion [3][4][5]. Previous studies reveal that supported metal oxide catalysts can be used for the alkane ODH reaction [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. For these catalysts the metal oxide loading and oxide support are important catalyst design parameter to be considered [5,[10][11][12][13][14][15][16][17].…”