Chemistry Reference
In-Depth Information
CzHa
catalyst
x + z = 12
y + a = 25
CxHy
+
C
10
H
21
100
Cl
90
Al
O
80
Cl
70
O
H
60
50
Fig. 7.11
Alkylation of benzene with 1-
alkene over AlCl
3
-HMS catalysts.
Crosses: AlCl
2
-HMS
24
-Ph
3
N; triangles:
AlCl
2
-HMS
24
-Ph
3
N; squares: AlCl
2
-K100;
diamonds: AlCl
3
.
6
8
10
12
14
16
proposed
catalyst
structure
Alkene chain length
extended the one-step preparation of organically
modified mesoporous materials [34,69] to prepare
mercaptopropyl-modified materials, which they
then oxidised using hydrogen peroxide to give a
supported sulfonic acid [80]. They have then utilised
this material in some acid-catalysed reactions.
The materials show excellent activity in the mono-
esterification of glycerol with fatty acids, a reaction
of significance in the preparation of emulsifiers
and one that is complicated by the similar react-
ivities of the three hydroxyl groups in glycerol
(Fig. 7.12).
Fig. 7.12
Preparation of a solid sulfonic acid and its use in
glycerol esterification.
possible with the homogeneous version. Eventually,
reaction stops as the pores become too small, but the
behaviour of the catalyst makes it a very promising
alternative to homogeneous aluminium chloride.
Similar results were obtained with catalysts of dif-
fering pore sizes over the range 1.6-2.4 nm.
Contributions to the replacement of sulfuric acid
also have been made. Jacobs & De Vos have
