In situ UV–Vis diffuse reflectance spectroscopy — on line activity measurements of supported chromium oxide catalysts: relating isobutane dehydrogenation activity with Cr-speciation via experimental design
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چکیده
منابع مشابه
Dehydrogenation of Isobutane with Carbon Dioxide over SBA-15-Supported Vanadium Oxide Catalysts
A series of vanadia catalysts supported on SBA-15 (V/SBA) with a vanadia (V) content ranging from 1% to 11% were prepared by an incipient wetness method. Their catalytic behavior in the dehydrogenation of isobutane to isobutene with CO2 was examined. The catalysts were characterized by N2 adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and temperatur...
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The molecular structures, oxidation states, and reactivity of 3 and 6% CrO3/ZrO2 catalysts prepared by incipient wetness impregnation were examined under different conditions. The in situ Raman spectroscopic studies under dehydrated conditions reveal that the 3 and 6% CrO3/ZrO2 catalysts possess equal amounts of monochromate and polychromate species. Consequently, monolayer coverage on this ZrO...
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The isothermal isotopic exchange reaction of O2 with 16O of chromium(VI) oxide supported on zirconia, alumina, and titania has been investigated with in situ laser Raman spectroscopy. The isotopic exchange reaction is dependent on the support type, the Cr loading, and the reaction temperature. Complete isotopic exchange of chromium(VI) oxide with O2 is difficult to achieve and requires several ...
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The IR spectra of bulk Nb2O5‚nH2O and niobia supported on SiO2, Al2O3, ZrO2, and TiO2 were recorded in the fundamental and overtone NbdO regions, as well as in the hydroxyl region, to develop a better understanding of the structural models of surface NbOx species. The coincidence of the IR and Raman fundamental NbdO frequency in Nb2O5/Al2O3, Nb2O5/ZrO2, and Nb2O5/TiO2 provides the strongest evi...
متن کاملSitu 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...
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ژورنال
عنوان ژورنال: Journal of Molecular Catalysis A: Chemical
سال: 2000
ISSN: 1381-1169
DOI: 10.1016/s1381-1169(99)00259-9