Oxidative dehydrogenation of ethylbenzene on activated carbon catalysts 3. Catalyst deactivation

• Type: Article in International Scientific Journal
• Date: 2001

Authors

Manuel Fernando R Pereira (Author) FEUP; José Melo Orfão (Author) FEUP; José Luis Figueiredo (Author) FEUP

Journal

Title: Applied Catalysis A: General

Vol. 218

Pages: 307-318

ISSN: 0926-860X

Publisher: Elsevier

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ISI Web of Knowledge - 80 Citations

ISI Web of Science

Scopus - 91 Citations

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Other information

Authenticus ID: P-000-T88

DOI: 10.1016/s0926-860x(01)00657-3

Abstract (EN): Extended catalytic tests show that coke deposition is responsible for the deactivation of activated carbon catalysts in the oxidative dehydrogenation of ethylbenzene (ODE). Temperature-programmed desorption (TPD), DRIFTS, textural and elemental analyses of used catalysts have shown that not only the great majority of the micropores become blocked, but also that the amounts of oxygen and hydrogen in the catalyst composition increase with time on stream, leading to a material increasingly more reactive towards oxidation. It was observed that after a few days on stream, the rate of carbon gasification became larger than the rate of coke deposition, leading to a decrease in catalyst weight. Working under milder conditions (lower temperature and oxygen partial pressure) delayed this effect. The increase in the concentration of surface groups with time does not result in a proportional increase in the activity of the catalysts, because the majority of the groups created are not active for the ODE reaction.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12