Commercial silica-alumina catalysts prepared by different procedures have been characterized. Both present strong Lewis acidity together with Brønsted sites able to protonate pyridine. No evidence of "zeolitic" bridging OH's but significant heterogeneity of terminal silanol groups, part of which are likely "pseudobridging", was found. Similar high activity in ethanol conversion but markedly different selectivities to ethylene and diethyl ether were found. They are less active than both zeolites and γ-Al2O3. Lewis sites with alumina-like acidobasic neighbor are more selective for ethylene production while Lewis sites with silica-like covalent neighbor are more selective for diethyl ether.

Ethanol dehydration on silica-aluminas: Active sites and ethylene/diethyl ether selectivities

PHUNG, THANH KHOA;BUSCA, GUIDO
2015-01-01

Abstract

Commercial silica-alumina catalysts prepared by different procedures have been characterized. Both present strong Lewis acidity together with Brønsted sites able to protonate pyridine. No evidence of "zeolitic" bridging OH's but significant heterogeneity of terminal silanol groups, part of which are likely "pseudobridging", was found. Similar high activity in ethanol conversion but markedly different selectivities to ethylene and diethyl ether were found. They are less active than both zeolites and γ-Al2O3. Lewis sites with alumina-like acidobasic neighbor are more selective for ethylene production while Lewis sites with silica-like covalent neighbor are more selective for diethyl ether.
File in questo prodotto:
File Dimensione Formato  
CATCOMM SA.pdf

accesso chiuso

Descrizione: articolo pubblicato
Tipologia: Documento in versione editoriale
Dimensione 1.23 MB
Formato Adobe PDF
1.23 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

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/11567/826612
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 80
  • ???jsp.display-item.citation.isi??? 73
social impact