On the catalyst features affecting selectivity in n-C 4 hydrocarbon oxidation and oxidative dehydrogenation. Ft-IR studies

The interaction of butane, butenes and butadiene, as well as of some oxygenated compounds with Mg vanadate, (VO) 2P 2O 7 and V 2O 5-TiO 2 catalysts has been investigated by Ft-IR spectroscopy in the 150-900 K temperature range. A common reaction scheme has been identified. The catalytic activity and selectivities to oxidative dehydrogenation products (main useful products on V-Mg-O), to acetic acid and COx (predominant on V-Ti-O) and to maleic anhydride (predominant on V-P-O) are proposed to depend on the efficiency of the different active sites (Lewis acidic V centers acting as alkylic and allylic CH activation sites, OH's bonded to oxidizing V ions, V=0 oxygen insertion sites) observed through surface characterization studies over the different catalyst surfaces. \ua9 1994 Elsevier Science B.V. All rights reserved