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Aldol condensation of citral and acetone over mesoporous catalysts obtained by thermal and chemical activation of magnesium–aluminum hydrotalcite-like precursors

Paper ID Volume ID Publish Year Pages File Format Full-Text
44565 46041 2006 8 PDF Available
Title
Aldol condensation of citral and acetone over mesoporous catalysts obtained by thermal and chemical activation of magnesium–aluminum hydrotalcite-like precursors
Abstract

Hydrotalcite-like materials containing a various amount of magnesium and aluminum cations in the brucite like sheets, and carbonate/nitrate anions in the interlayer space were synthesized by the coprecipitation method. The as-prepared samples were characterized with respect to structure (XRD), chemical composition (elemental analysis and XRF) and thermal stability (evolved gas analysis by mass spectrometry). The thermal treatment of the hydrotalcite-like compounds at an elevated temperature (450–600 °C) resulted in a structural transformation of the layer structure into mixed Mg–Al oxides. The textural and acid–base properties of such materials were examined by low-temperature sorption of N2 and temperature-programmed desorption of NH3 and CO2, respectively. An influence of chemical composition and pre-treatment conditions on the catalytic activity and selectivity of the hydrotalcite-derived oxides in the self-condensation of acetone and the cross-condensation of citral and acetone was discussed. The pseudoionone yield was significantly enhanced by rehydration of the hydrotalcite-derived catalysts. The rehydrated samples showed a higher catalytic activity than Ba(OH)2, which was tested as a standard catalyst of aldol condensation process.

Keywords
Aldol condensation; Aceton; Citral; Hydrotalcite-derived catalysts
First Page Preview
Aldol condensation of citral and acetone over mesoporous catalysts obtained by thermal and chemical activation of magnesium–aluminum hydrotalcite-like precursors
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 302, Issue 2, 11 April 2006, Pages 317–324
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis