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Liquid phase catalytic oxidation of isophorone with tert-butylhydroperoxide over Cu/Co/Fe–MgAl ternary hydrotalcites

Paper ID Volume ID Publish Year Pages File Format Full-Text
43331 45964 2008 8 PDF Available
Title
Liquid phase catalytic oxidation of isophorone with tert-butylhydroperoxide over Cu/Co/Fe–MgAl ternary hydrotalcites
Abstract

Liquid phase catalytic oxidation of isophorone was carried out over M–MgAl ternary hydrotalcites, where M is Cu, Co or Fe, using tert-butylhydroperoxide (TBHP) as an oxidant. The influence of various reaction parameters, namely, substrate/catalyst mass ratio, substrate:oxidant mole ratio, nature of oxidant, solvent, reaction temperature and reaction time on the activity and selectivity for the desired reaction, were studied. The catalysts were synthesized by the coprecipitation technique using metal nitrates and a NaOH/Na2CO3 mixture. Powder X-ray diffraction and thermal analysis of these samples confirmed the presence of hydrotalcite like layered network. Oxidation of isophorone over these catalysts resulted mainly in the formation of ketoisophorone (KIP). A maximum isophorone conversion of 74% with 100% selectivity to KIP was observed over CuMgAl-13 at 333 K up to 48 h using acetonitrile as a solvent, followed by CoMgAl-13 (36%) and FeMgAl-13 (25%). The redox properties of transition metal ions played an important role in driving the reaction and a reaction mechanism involving predominantly free radicals were proposed. An increase in the conversion of isophorone was observed with decreasing substrate/catalyst mass ratio down to 20. With respect to the influence of reaction temperature, the conversion increased up to 333 K and decreased when the temperature was further increased. Among the solvents studied acetonitrile showed maximum conversion and selectivity to KIP, where as methanol showed minimum conversion. An increase in the conversion of isophorone was observed with decreasing molar ratio of isophorone to TBHP. A gradual increase in the conversion of isophorone was observed with reaction time and the maximum conversion was observed at 48 h. Reusable studies showed that the catalysts were stable and reusable up to three cycles without substantial loss of activity.

Graphical abstractLiquid phase catalytic oxidation of isophorone was carried out over M–MgAl ternary hydrotalcites, where M is Cu, Co or Fe, using tert-butylhydroperoxide (TBHP) as an oxidant. Among the catalysts studied, CuMgAl-13 showed maximum conversion (74% KIP yield) at 60 °C up to 48 h using acetonitrile as a solvent. Moreover, the catalysts were stable after the reaction and were reusable without substantial loss of activity.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Isophorone oxidation; Ketoisophorone; Ternary hydrotalcites; Coprecipitation; tert-Butylhydroperoxide; Substrate/catalyst mass ratio
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Liquid phase catalytic oxidation of isophorone with tert-butylhydroperoxide over Cu/Co/Fe–MgAl ternary hydrotalcites
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 345, Issue 1, 31 July 2008, Pages 104–111
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us