Catalytic epoxidation of limonene

Article abstract of DOI:10.3390/50300336

The epoxidation of limonene with hidrogen peroxide was studied over zeolite Ti-beta (a large pore material) and heteropoly acids on carbono and alumina supported. PW₁₁/C was catalyst the best tested.

Full text of DOI:10.3390/50300336

336
Molecules 2000, 5
Catalytic Epoxidation of Limonene
E. Herrero, S. Casuscelli, J. Fernandez, C. Poncio, M. Rueda and O. Oyola
CITeQ, Universidad Tecnológica Nacional, Facultad Regional Córdoba, C.C.36, 5016 Córdoba, Ar-
gentina
Tel: 0351-4690585, E-mail: eherrero@sa.frc.utn.edu.ar
Abstract: The epoxidation of limonene with hidrogen peroxide was studied over zeolite Ti-
beta (a large pore material) and heteropoly acids on carbono and alumina supported. PW11/C
was catalyst the best tested.
Introduction
In the last years, the increase in environmental restrictions lead to the search for new oxydant sys-
tems to replace the traditionals in order to avoid the generation of polluting effluents.
The terpenes containing oxygen are very important to be used in the fragrances production; in our
country we have great quantities of limonene and thus we studied its oxydation to 1,2-epoxilimonene
using a heterogeneous catalysts system.
In a previous paper the pillared clays from mixed oligomers of Si-Ti [1] were studied, in this paper
the results using supported heteropolyacids (HPA) an zeolites Ti-beta are shown.
Experimental
The HPA were prepared from phosphomolybdic acid (PMA) and tunstophosphoric acid (TPA) and
then impregnated on alumina (A) or carbon (C) to fill the pores with solution in ethanol-water [2].
PW11 refers to a lacunar phase supported on C. Ti-beta zeolite (Ti-β) was prepared according to [3].
The reactions were run in a batch type glass reactor with vigorous stirring and at 343°K, the rate li-
monene/H2O2(35%) = 4 and 100 mg of catalysts and acetonitrile as solvent; the reaction was followed
by taking samples at different times and analyzing them by GLC, the remanent H2O2 was determined
by iodometric titration. The reaction products were identified by comparation with chromatographic
authentic samples and mass spectroscopy.
Results and Discussion
Limonene and H2O2 conversion and products selectivity at time on strem 7 hours, are shown in the
next table.

337
Molecules 2000, 5
CATALYSTS
CONVERSION
SELECTIVITY
(mmoles HPA/g ) % max.
H2O2
54,93
33,92
65,36
33,46
71,58
71,51
H2O2 Epoxide Cetones
Others
25,92
35,56
29,25
42,94
11,04
23,86
TPA/A (1.120)
TPA/C (0,855)
MPA/A (1.280)
MPA/C (0,649)
PW11/C (0,820)
Ti-β (2,6%TiO2)
33,85
13,03
34,62
22,35
38,22
46,21
61,63
38,41
52,96
66,80
53,40
63,62
31,20
22,95
36,89
24,28
58,74
22,94
42,88
41,49
33,86
32,78
30,23
54,60
We can observe that supported HPA on A show a higher conversion and selectivity to the epoxide
than the supported on C, which are more selective to other products (glycols and acid catalysis prod-
ucts), owing to a lower interaction between HPA and support. The catalyst with higher activity is Ti-β
but the more selective is the lacunar phase PW11/C, with high yield of epoxide derivative, because this
phase has a vacancy compared with Keggin structure, whic is active for oxydation reactions.
Acknowledgements: The authors are grateful to Hernan Gabeta for experimental collaboration and fi-
o
nancial support from CONICOR (project N 4230/97).
References and Notes
1. Herrero, E.R.; Casuscelli, S.G.; Nievas, M.L.; Ricaud, J. XI SINAQO (1997), Actas QOS-56.
2. Vazquez, P.; Pizzio, L.; Blanco, M.; Cáceres, C. XVI Simp.Ib.de Catál. (1998), Actas II, 1461 y
III, 2123.
3. Blasco, T. et al. J. Phys. Chem. B 1998, 102, 75.