FT-IR Spectroscopic Studies of Tin-Modified Rhenium Alumina-Silica Metathesis Catalyst

• Autorzy: Zawadzki J. , Skupiński W. , Kirszensztejn P. , Wachowski L. , Jamróz M. H. , Dobrowolski J. Cz.
• Języki publikacji: EN

Abstrakty

EN

FT-IR spectra of the products obtained in each step of the tetramethyltin (TMT)/3-wt. % Re2O7/Al2O3-SiO2 and TMT/Al2O3-SiO2 systems preparation are presented and discussed. The obtained spectra show that TMT reacts with alumina-silica hydroxyl groups already at room temperature, yielding surface methyltin compounds; NH4ReO4 reacts with alumina–silica surface at temperatures up to 423 K, yielding rhenium surface species and ammonia, which is strongly bonded by acidic sites of the Brönsted kind. FT-IR spectrum of the system TMT/3-wt.%Re2O7/Al2O3-SiO2 indicated the absence of surface methyl tin compounds observed on the surface system TMT/Al2O3-SiO2, and the presence of physically adsorbed TMT; after 5 h of evacuation of the TMT/3-wt. % Re2O7- /Al2O3-SiO2 system, the FT-IR spectrum indicated the presence of only a single band at 2977 cm–1, which may be assigned to the C–H bond stretching of the methyl group in the surface bridged (O, O) Re(=O)2CH3 complexes formed. Analysis of FT-IR results suggests formation of a new phase containing rhenium and aluminium ions, on which olefin sites active in olefin metathesis are formed in the system studied.

• Wydawca: Polskie Towarzystwo Chemiczne
• Czasopismo: Polish Journal of Chemistry
• Rocznik: 2000
• Tom: Vol. 74, nr 12
• Strony: 1755--1767
• Opis fizyczny: Bibliogr. 22 poz., rys.

Twórcy

autor

Zawadzki J.

autor

Skupiński W.

autor

Kirszensztejn P.

autor

Wachowski L.

autor

Jamróz M. H.

autor

Dobrowolski J. Cz.

• Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, PL-00-664 Warszawa, Poland