Since the relevance of deactivation phenomena in heterogeneous gas-solid photocatalytic processes, a study on the deactivation of MoOx/TiO2 catalysts in the oxidative photodehydrogenation of cyclohexane has been carried out in a fixed bed reactor and compared to the behavior of catalysts used in a two-dimensional fluidized bed photoreactor. Superior photocatalytic performances were obtained in the fluidized bed reactor with respect to the fixed bed reactor both in terms of cyclohexane conversion and benzene yield. At the opposite of the fixed bed, in the fluidized bed reactor, catalyst did not deactivate. Characterization performed on catalysts after photocatalytic tests evidenced that the deactivation of the catalysts is correlated to the accumulation of carbonaceous species on catalyst surface and the sulfur disappearance. The catalysts used in fluidized conditions remained active as they maintained their initial sulfur content at the surface.

Avoiding the deactivation of sulphated MoOx/TiO2 catalysts in the photocatalytic cyclohexane oxidative dehydrogenation by a fluidized bed photoreactor.

SANNINO, Diana;VAIANO, VINCENZO;CIAMBELLI, Paolo;
2011

Abstract

Since the relevance of deactivation phenomena in heterogeneous gas-solid photocatalytic processes, a study on the deactivation of MoOx/TiO2 catalysts in the oxidative photodehydrogenation of cyclohexane has been carried out in a fixed bed reactor and compared to the behavior of catalysts used in a two-dimensional fluidized bed photoreactor. Superior photocatalytic performances were obtained in the fluidized bed reactor with respect to the fixed bed reactor both in terms of cyclohexane conversion and benzene yield. At the opposite of the fixed bed, in the fluidized bed reactor, catalyst did not deactivate. Characterization performed on catalysts after photocatalytic tests evidenced that the deactivation of the catalysts is correlated to the accumulation of carbonaceous species on catalyst surface and the sulfur disappearance. The catalysts used in fluidized conditions remained active as they maintained their initial sulfur content at the surface.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

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: http://hdl.handle.net/11386/3034637
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 39
  • ???jsp.display-item.citation.isi??? 39
social impact