FTIR and microcalorimetric analysis of adsorbed pyridine has been employed for the characterisation of a set of Fe-MFI zeolite catalysts with different Si/Al and Si/Fe ratios, used for the gas phase hydroxylation of benzene to phenol by N2O. Catalysts behaviour in terms of activity and deactivaton rate is discussed in relation to the nature, concentration and strength of their surface acid sites. Surface acidity, though not involved directly in the hydroxylation reaction, plays a major role in determining catalyst lifetime. Coke formation, leading to catalyst deactivation, is triggered by further undesired reactions of phenol and is favoured by the strong adsorption of the latter on Lewis acid sites, restraining its diffusion out of the zeolite pores.

Effect of surface acidity on the behaviour of Fe-MFI catalysts for benzene hydroxylation to phenol / E. Selli, I.G. Rossetti, D. Meloni, F. Sini, L. Forni. - In: APPLIED CATALYSIS A: GENERAL. - ISSN 0926-860X. - 262:2(2004), pp. 131-136.

Effect of surface acidity on the behaviour of Fe-MFI catalysts for benzene hydroxylation to phenol

E. Selli
Primo
;
I.G. Rossetti
Secondo
;
L. Forni
Ultimo
2004

Abstract

FTIR and microcalorimetric analysis of adsorbed pyridine has been employed for the characterisation of a set of Fe-MFI zeolite catalysts with different Si/Al and Si/Fe ratios, used for the gas phase hydroxylation of benzene to phenol by N2O. Catalysts behaviour in terms of activity and deactivaton rate is discussed in relation to the nature, concentration and strength of their surface acid sites. Surface acidity, though not involved directly in the hydroxylation reaction, plays a major role in determining catalyst lifetime. Coke formation, leading to catalyst deactivation, is triggered by further undesired reactions of phenol and is favoured by the strong adsorption of the latter on Lewis acid sites, restraining its diffusion out of the zeolite pores.
Fe-MFI catalyst ; Benzene hydroxylation by N2O ; Brønsted acid sites ; Lewis acid sites and Catalyst deactivation
Settore CHIM/02 - Chimica Fisica
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/14882
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 23
  • ???jsp.display-item.citation.isi??? 21
social impact