Please use this identifier to cite or link to this item:
|Title: ||Heterogeneous Catalysts: Design, Applications and Research Insights|
|Authors: ||Castanheiro, J|
|Editors: ||Jensen, Kurt|
|Keywords: ||USY zeolite|
|Issue Date: ||12-Dec-2016|
|Publisher: ||Nova Science Publishers|
|Citation: ||C.S. Caetano, M. Caiado, J.E. Castanheiro*, “Cyclization of Pseudoionone over USY Zeolites”, pp. 177-193, Chapter 4, Heterogeneous Catalysts: Design, Applications and Research Insights, Kurt Jensen (Ed.), Nova Science Pub. Inc., New York, 2016|
|Abstract: ||The cyclization of pseudoionone yields a mixture of alpha-ionone, beta-ionone and gamma-ionone. By careful control of reagent and reaction conditions, either the alpha- and beta- isomer can be favoured. The alpha-ionone has violet odour and is widely used in perfumery and flavours. beta-Ionone is the main precursor of Vitamin A and beta-carotene. Traditionally, strong homogeneous catalysts, like sulphuric acid and phosphoric acid have been used. These problems can be overcome by the use of solid acid catalysts.
This work reports the cyclization of pseudoionone over USY zeolites, at 80ºC. USY
It is observed that the initial activity increases with the Si/Al ratio of zeolite until a maximum, which is obtained with USY3. With higher Si/Al ratio, a decrease in the catalytic activity is observed.
Selectivity to ionone isomers is around 42 %, at 75% of pseudoionone conversion, after 24 h of reaction.
USY3 zeolite was reused four times with the same catalyst sample in the same condicions. It was observed a stabilization of the catalytic activity, after the second use.|
|Appears in Collections:||QUI - Publicações - Capítulos de Livros|
CQE - Publicações - Capítulos de Livros
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.