Activity for Dehydrogenation of Reduced Chromium Oxide-Alumina Catalysts

Catalytic Behavior of Chromium Oxide Supported on Nanocasting-Prepared Mesoporous Alumina in Dehydrogenation of Propane

Mesoporous alumina with narrow pore size distribution centered in the range of 4.4-5.0 nm and with a specific surface area as high as 270 m²·g-1 was prepared via the nanocasting approach using a CMK-3 carbon replica as a hard template. Based on this support, a series of catalysts containing 1, 5, 10, 20 and 30 wt % of chromium was prepared by incipient wetness impregnation, characterized, and s...

Pyridine Adsorption on Molybdenum Oxide-Alumina Catalysts

The adsorption of pyridine on a complete monolayer molybdenum oxide-Al203 catalyst was studied. Both Lewis and Bronsted acid sites are present on a catalyst with a Mo valence of -4.1. The orientation of adsorbed pyridine was studied by means of its interaction with surface OD groups, which leads to the formation of only 2-deuteriopyridine. The fraction of molybdenum ions active for hydrogenatio...

'H MAS NMR Studies of Alumina-Supported Metal Oxide Catalysts

The interactions of two-dimensional vanadium oxide and molybdenum oxide overlayers with the surface hydroxyls of an alumina support were examined with 'H MAS NMR spectroscopy. The measurements demonstrated that these surface metal oxide overlayers are homogeneously distributed over the alumina surface and essentially titrate all the accessible surface hydroxyls at monolayer coverage. The invest...

Situ Raman Spectroscopy of Alumina - Supported Metal Oxide Catalysts

The molecular structures of the surface overlayers of rhenium(VI1) oxide, molybdenum(V1) oxide, tungsten(V1) oxide, chromium(V1) oxide, vanadium(V) oxide, niobium(V) oxide, and titanium( IV) oxide on y-alumina were determined by in situ Raman spectroscopy under dehydrated conditions. It was found that the dehydrated surface metal oxide structures of all the systems under study, except for suppo...

Dehydrogenation by Heterogeneous Catalysts