The epoxidation of functionalised substrates of interest as fine chemicals using mesoporous titanium-containing silicas is here reported and the role of silylation in changing the surface hydrophilic character of these catalysts is investigated. The silylation procedure was carried out on two titanium-grafted silicas with different morphologies. An ordered MCM-41 and a non-ordered commercial mesoporous silica were used as supports. The reactivity of bulky substrates with different characteristics (limonene, a-terpineol, carveol and methyl linoleate) is studied and compared. The effect of silylation is more pronounced on Ti–MCM-41 than with low-surface area Ti–SiO2 and it is shown that the catalytic performances are strongly dependent on the nature of the reactant. Purely alkenic molecules show better reactivity over silylated catalysts than over non-silylated ones. On the other hand, a hydrophilic environment around the titanium active sites has often a beneficial effect in the epoxidation of richly functionalised substrates.

The effect of silylation on titanium-containing silica catalysts for the epoxidation of functionalised molecules

Guidotti M;Psaro R;
2008

Abstract

The epoxidation of functionalised substrates of interest as fine chemicals using mesoporous titanium-containing silicas is here reported and the role of silylation in changing the surface hydrophilic character of these catalysts is investigated. The silylation procedure was carried out on two titanium-grafted silicas with different morphologies. An ordered MCM-41 and a non-ordered commercial mesoporous silica were used as supports. The reactivity of bulky substrates with different characteristics (limonene, a-terpineol, carveol and methyl linoleate) is studied and compared. The effect of silylation is more pronounced on Ti–MCM-41 than with low-surface area Ti–SiO2 and it is shown that the catalytic performances are strongly dependent on the nature of the reactant. Purely alkenic molecules show better reactivity over silylated catalysts than over non-silylated ones. On the other hand, a hydrophilic environment around the titanium active sites has often a beneficial effect in the epoxidation of richly functionalised substrates.
2008
Istituto di Scienze e Tecnologie Molecolari - ISTM - Sede Milano
Silylation
Heterogeneous epoxidation catalysts
Hydrophobicity
Hydrophilicity
Titanium
File in questo prodotto:
File Dimensione Formato  
prod_48277-doc_23984.pdf

solo utenti autorizzati

Descrizione: MicropMesopMater2008
Dimensione 188.62 kB
Formato Adobe PDF
188.62 kB 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/20.500.14243/71466
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 45
social impact