Applied Catalysis A: General 219 (2001) 209–213
Alumina-catalyzed alkene epoxidation with hydrogen peroxide
Dalmo Mandelli
a
, Michiel C.A. van Vliet
b
, Roger A. Sheldon
b
, Ulf Schuchardt
c,∗
a
Instituto de Ciências Biológicas e Qu´ ımica, Pontif´ ıcia Universidade Católica de Campinas, P.O. Box 1111, 13020-904 Campinas, SP, Brazil
b
Laboratory of Organic Chemistry and Catalysis, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
c
Instituto de Qu´ ımica, Universidade Estadual de Campinas, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
Received 13 February 2001; received in revised form 30 May 2001; accepted 1 June 2001
Abstract
Inexpensive Al
2
O
3
can be used as a simple catalyst for alkene epoxidation, using anhydrous hydrogen peroxide as oxidant.
This system is active and selective in the epoxidation of several alkenes. Besides the epoxidation of the terpenes limonene and
-pinene, we studied the epoxidation of cyclohexene and cyclooctene, as well as -olefins, such as 1-octene and 1-decene.
Productivities of up to 4.3 g products per gram catalyst were obtained and the catalyst was recycled without significant loss
of activity. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Alumina; Heterogeneous catalysis; Epoxidation; Hydrogen peroxide
1. Introduction
Alkene epoxidation is a very useful reaction in in-
dustrial organic synthesis. Epoxides are key raw ma-
terials for a wide variety of products [1,2] and much
effort is devoted to the development of new active and
selective epoxidation catalysts for processes that avoid
the formation of large amounts of by-products.
The simplest oxirane, ethylene oxide, is obtained
by vapor-phase oxidation of ethylene with oxygen
or air, using a supported silver catalyst [3]. Unfortu-
nately, this method is not applicable to alkenes with
allylic C–H bonds, due to oxidation in this position,
giving a mixture of products. For substituted alkenes,
liquid-phase epoxidation with peracids is still the most
widely used method, in spite of being a slow reaction
Part of the results was presented at the XVII Simp´ osio
Iberoamericano de Cat´ alise, Porto, Portugal, July 2000, p. 523.
∗
Corresponding author. Tel.: +55-19-3788-3071;
fax: +55-19-3788-3023.
E-mail address: ulf@iqm.unicamp.br (U. Schuchardt).
and producing large amounts of carboxylic acids as
side products. An alternative is the use of hydrogen
peroxide as oxidant, which gives a clean and environ-
mentally friendly reaction, since the starting material
is safe and inexpensive and only water is formed as
by-product [4]. Reactions with H
2
O
2
generally require
the presence of a catalyst. In spite of considerable
research efforts during the last decades, only a few
useful catalytic systems for epoxidation with H
2
O
2
have been developed. These include tungsten [5–8],
manganese [9–11], and rhenium [12–14] based sys-
tems. However, industrial application of these systems
is not simple due to high catalyst costs and difficulties
in separating the catalyst from the product. Therefore,
the development of stable heterogeneous catalysts for
the epoxidation of alkenes with H
2
O
2
is a current
challenge. Few systems are efficient in such reactions,
e.g Ti-silicalite [15], vanadium containing silicates
[16], Ti-pillared clays [17] or hydrotalcites [18,19].
In 1977, Leffler and Miller [20] showed that dif-
ferent kinds of Al
2
O
3
react with organic peroxides,
yielding Al–OOH surface species, which decompose
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