Geoscience Reference
In-Depth Information
Sodalite
Silicon or
Aluminum
Oxygen
Zeolite A
14
Sodalite cage
12
Faujasite
(C
4
F
9
)
3
N
10
C
6
H
3
(C
3
H
7
)
3
8
C
5
H
12
C
6
H
12
6
C
6
H
14
O
2
H
2
O
4
2
σ
(Å)
Pore size (Å)
Figure 6.3 Continued
Group
SBUs
1
Single 4 ring (S4R)
2
Single 6 ring (S6R)
3
Single 8 ring (S8R)
4
Double 4 ring (D4R)
5
Double 6 ring (D6R)
6
Double 8 ring (D8R)
7
Complex 4-1, T
5
O
10
unit
8
Complex 5-1, T
8
O
16
unit
9
Complex 4-4-1, T
10
O
20
unit
Qinhua and Aizhen
[28]
have summarized the structure of zeolites as follows: the
primary building block (SiO
4
)
4
2
tetrahedron (
Figure 6.4a
) and the tetrahedra are
connected through their corners of shared oxygen atoms to form a wide range of
small SBUs (
Figure 6.4b
). They are interconnected to form a wide range of polyhe-
dra (
Figure 6.4c
), which in turn connect to form the infinitely extended frameworks
of the various specific zeolite crystal structures. In
Figure 6.4a
d
, showing the
