resumo
Ferrocenium ions, [Fc](+), have been immobilised in the microporous titanosilicate ETS-10 by ion exchange of Na+/K+ ions under hydrothermal conditions. The resultant hybrid inorganic-organometallic (ETS-10/[Fc](+)) material was characterised by elemental analysis, diffuse reflectance UV-Vis spectroscopy, FT-IR spectroscopy, powder X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The ETS-10/[Fc](+) sample was tested as a catalyst for the isomerisation of alpha-pinene oxide (PinOx) at 35 degrees C. With alpha,alpha,alpha-trifluorotoluene (TFT) as solvent, campholenic aldehyde (CPA) was the main product formed in 38% yield at 100% conversion and 30 min reaction. Other reaction products included trans-carveol, iso-pinocamphone and trans-pinocarveol. The same PinOx conversion and CPA yield could be reached within 1 min reaction time by increasing the reaction temperature (to 55 degrees C) and the Fe:PinOx molar ratio. Other solvents (hexane, CH3CN, toluene) led to poorer results than TFT. Characterisation of the used catalyst, together with an analysis of the catalytic activity of the liquid phase obtained after contact of ETS-10/[Fc](+) with TFT, indicated that the ETS-10/[Fc](+) sample was resistant toward leaching of iron-containing active species. When the recovered solid was reused in a second batch run, catalytic activity was lower than in the first run, while selectivity to CPA was higher. (C) 2015 Elsevier B.V. All rights reserved.
palavras-chave
MICROPOROUS TITANOSILICATE ETS-10; LEWIS-ACID; PHOTOCATALYTIC DEGRADATION; CAMPHOLENIC ALDEHYDE; NANOPARTICLES; FE(CP)(2)BF4; SELECTIVITY; COMPLEXES; MOLECULES; CHEMISTRY
categoria
Chemistry
autores
Bruno, SM; Gomes, AC; Coelho, AC; Brandao, P; Valente, AA; Pillinger, M; Goncalves, IS
nossos autores
Ana Catarina Costa Gomes Alves
Investigador Auxiliar
Anabela Tavares Aguiar Valente
Investigador Principal
Isabel Maria de Sousa Gonçalves
Professor associado
Martyn Pillinger
Investigador Principal
Paula Cristina Ferreira da Silva Brandão
Investigador Auxiliar
Sofia M. Bruno
Investigador AuxiliarProjectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
Use of molecular containers to modify metallocene-based catalysts (PTDC/QEQ-SUP/1906/2012)
agradecimentos
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials [FCT (Fundacao para a Ciencia e a Tecnologia) ref. UID/CTM/50011/2013], financed by national funds through the FCT/MEC and when applicable co-financed by FEDER (Fundo Europeu de Desenvolvimento Regional) under the PT2020 Partnership Agreement. We acknowledge funding by FEDER through COMPETE (Programa Operacional Factores de Competitividade) and by national funds through the FCT within the project FCOMP-01-0124-FEDER-029779 (FCT ref. PTDC/QEQ-SUP/1906/2012, including the research grant with ref. BPD/UI89/4864/2013 to A.C.G.). The FCT and the European Union are acknowledged for a post-doctoral grant to S.M.B. (ref. SFRH/BPD/46473/2008) cofunded by MCTES and the European Social Fund through the program POPH of QREN.