Dehydrogenation of Methylcyclopentane over Chromia-Alumina Catalysts

Heinemann, H.

doi:10.1021/ie50501a035

Cited by 7 publications

(1 citation statement)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, other authors suggest that this relation is not so clear. Heineman 24 has reported that during methylcyclopentane dehydrogenation, the decrease in the amount of the coke does not considerably modify global conversion. However, more recently Gorriz et al 25 have demonstrated in supported chromia on alumina catalysts that the amount of coke formed and the deactivation rate are a function of the chromium content and its dispersion, this being higher at higher amounts of supported chromia.…”

Section: T H I S C O N T E N T Imentioning

confidence: 99%

Dehydrogenation of Propane over Chromia-Pillared Zirconium Phosphate Catalysts

1999

View full text Add to dashboard Cite

Two series of porous chromia-pillared α-zirconium phosphate materials, prepared using two different methods of colloidization of the initial phase and with variable chromium contents (CrZrP-Xa and CrZrP-Xb) have been tested in the oxidative and nonoxidative dehydrogenation of propane in a flow reactor at atmospheric pressure. All catalysts are highly selective to propene under nonoxidative conditions at 823 K. In both series of catalysts, the initial activity increases with the chromium content, but generally CrZrP-Xb catalysts are more active than those of series CrZrP-Xa, which is in good agreement with their higher chromium contents and greater dispersions. In all cases, deactivation was detected due to coke formed from undesired reactions. When the reactions were carried out under oxidative conditions at 673 K, the activities were enhanced and the observed deactivation was minimum. The activities found vary between 0.47 and 1.31 μmol of propene g-1 s-1 and are maintained after 200 min of reaction. These activity values were also related to the chromium content, being slightly higher for CrZrP-Xb materials. A parallel study to evaluate the influence of acidity in the obtained results has been carried out. The activities found of these catalysts seem to be related to the presence of Cr(III) centers with vacancies in their coordination sphere. These vacancies, in nonoxidative conditions, can activate the reactive molecules originating propene and hydrogen. On the other hand, in an oxidative atmosphere, Cr(III) species can activate oxygen molecules, through an electronic transference process, yielding propene and water.

show abstract

Section: T H I S C O N T E N T Imentioning

confidence: 99%