Styrene oligomerization catalyzed by zeolites of different structural types

Article abstract of DOI:10.1134/S0965544110020088

It was shown that styrene oligomerization in the presence of the zeolite ZSM-12 in a solvent (chlorobenzene) as well as without it proceeds with a high conversion (98-100 wt %) and a high selectivity for linear dimers (up to 82%). The main oligomerization products in the presence of the zeolite Beta are dimers (70-80%), mostly the linear isomer trans-1,3-diphenylbut-1-ene. In the presence of the less active zeolite Y, styrene gives a complex mixture of oligomers in which dimers (53-60%, in chlorobenzene) or dimers and trimers (60-80%, in bulk) are predominant.

Full text of DOI:10.1134/S0965544110020088

ISSN 0965ꢀ5441, Petroleum Chemistry, 2010, Vol. 50, No. 2, pp. 129–134. © Pleiades Publishing, Ltd., 2010.
Original Russian Text © N.G. Grigor’eva, R.R. Talipova, L.Ph. Korzhova, S.V. Bubennov, B.I. Kutepov, U.M. Dzhemilev, 2010, published in Neftekhimiya, 2010, Vol. 50, No. 2, pp. 125–
1
29.
Styrene Oligomerization Catalyzed by Zeolites
of Different Structural Types
N. G. Grigor’eva, R. R. Talipova, L. Ph. Korzhova, S. V. Bubennov,
B. I. Kutepov, and U. M. Dzhemilev
Institute of Petroleum Chemistry and Catalysis, Russian Academy of Sciences, Ufa, Russia
eꢀmail: grigꢀng@mail.ru
Received March 1, 2009
Abstract—It was shown that styrene oligomerization in the presence of the zeolite ZSMꢀ12 in a solvent
(chlorobenzene) as well as without it proceeds with a high conversion (98–100 wt %) and a high selectivity
for linear dimers (up to 82%). The main oligomerization products in the presence of the zeolite Beta are
dimers (70–80%), mostly the linear isomer transꢀ1,3ꢀdiphenylbutꢀ1ꢀene. In the presence of the less active
zeolite Y, styrene gives a complex mixture of oligomers in which dimers (53–60%, in chlorobenzene) or
dimers and trimers (60–80%, in bulk) are predominant.
DOI: 10.1134/S0965544110020088
It is known that styrene forms linear (transꢀ1,3ꢀ styrene dimerization selectively and under mild conꢀ
diphenylbutꢀ1ꢀene, Ia) and cyclic (cisꢀ and transꢀisoꢀ ditions.
mers of 1ꢀmethylꢀ3ꢀphenylindane, IIa IIb) dimers, as
,
well as a large amount of oligomers, in the presence of
acid catalysts [1–5].
EXPERIMENTAL
The dimers of styrene can be applied as regulators
for controlling the molecular weights of various polyꢀ
mers [6], plasticizers [7], a base stock of synthetic
lubricants [8, 9], and components of epoxy resins and
paintꢀandꢀvarnish materials [10].
The following zeolites in their H forms were invesꢀ
tigated in the present work: Y (SiO /Al O = 6.0;
2
2
3
+
+
Na
according to the procedure described in [16], Beta
SiO /Al O = 18), and ZSMꢀ12 (SiO /Al O = 34)
/
H
ion exchange degree 96%) synthesized
(
2
2
3
2
2
3
For the synthesis of dimers with a 90% or higher
selectivity, it was proposed [4, 11–13] to carry out the
reaction in the presence of strong acids, such as
CF SO H and AcClO4. Similar results were obtained
produced by OAO Angarsk Plant of Catalysts and
Organic Synthesis. The samples of the catalysts were
precalcined in an air atmosphere for 4 h at 540°С. Styꢀ
rene was distilled prior to use, its purity was 99.0 wt %.
3
3
with the use of zeolites Y and Beta [14, 15]. For examꢀ
ple, the linear dimer was synthesized with a selectivity
The oligomerization of styrene was carried out in
of 81% in the presence of zeolite Y with a degree of an isothermal batch reactor at 80–120°С in the presꢀ
proton exchange of 10% (55 wt % of the catalyst, conꢀ ence of 5–30 wt % of the zeolite catalysts in chloꢀ
centration of styrene in CH Cl 0.2 mol/l, 25°С), [14] robenzene as well as without a solvent. The initial conꢀ
2
2
and the cyclic dimers were obtained with a selectivity centration of styrene in chlorobenzene [М]
was varꢀ
0
of 84–90% on zeolite Beta (500–1000 wt % of the catꢀ ied from 0.88 to 8.8 mol/l.
alyst, concentration of styrene in CCl 0.02 mol/l,
4
The current styrene concentration and quantitative
composition of the dimers were determined by GLC
analysis with a Carlo Erba HRGS 5300 Mega Series
chromatograph equipped with a flameꢀionization
detector: 25ꢀm glass capillary column, stationary
phase SEꢀ30, column temperature 50–280°С
72°С) [15].
It should be pointed out that the synthesis of the
styrene linear dimer is performed in the presence of
large amounts of both the catalyst and solvent, which
considerably decreases the preparative value of the
method. As there are no comments in the published
works regarding the choice of reaction conditions, it
can be assumed that such reaction parameters are
caused by the low activity of the catalysts or their fast
deactivation by the resulting products.
(
8°C/min), detector temperature 250°С, vaporizer
temperature 300°С, and helium as the carrier gas
30 ml/min). The retention times (min) for the dimers
were as follows: cisꢀ1,3ꢀdiphenylbutꢀ1ꢀene, 15.2; cisꢀ
ꢀmethylꢀ3ꢀphenylindane, 15.6; transꢀ1ꢀmethylꢀ3ꢀ
(
1
The goal of our work is the development of effective phenylindane, 15.9; and transꢀ1,3ꢀdiphenylbutꢀ1ꢀ
zeolite catalysts of various structural types, which ene, 17.1; the retention times of the trimers were
would make it possible to carry out linear and cyclic 26.2–28.4 (12 peaks).
129

130
GRIGOR’EVA et al.
Table 1. Bulk oligomerization of styrene in the presence of different zeolites
Reaction conditions
Styrene conꢀ
version,
wt %
Oligomer composition, wt %
= 3 = 4 = 5
Catalyst
I : II ratio
[
kt], wt %
T
,
°
C
time, h
n
= 2
n
n
n
n = 14
Y
5
0
0
10
10
110
80
110
110
110
1
1
1
1
1
18.5
16.0
20.9
68.9
82.5
37.3
18.6
50.8
69.0
79.3
25.0
12.2
32.5
24.0
20.2
11.1
8.1
10.1
5.1
4.1
2.9
2.3
1.9
–
22.5
58.2
4.3
–
60 : 40
58 : 42
55 : 45
65 : 35
77 : 23
1
1
Beta
ZSMꢀ12
0.5
–
[kt] – catalyst concentration, % of styrene mass.
The identification of the styrene dimers was perꢀ analyzed by using the polystyrene calibration perꢀ
formed by GC–MS analysis, as well as by a compariꢀ formed in accordance with the Aldrich standards.
son of the resulting data with those known from pubꢀ
lished data [14]. The analysis was carried out with an
FISONS TRIO 1000 instrument under the following
RESULTS AND DISCUSSION
conditions: GC: column temperature, 50–320°С
4°C/min), vaporizer temperature 260°С, helium as
the carrier gas (1 cm /min), split ratio 1 : 100; MS in
The bulk (solventꢀfree) oligomerization of styrene
in the presence of zeolites leads to a complex mixture
of oligomers (Table 1), in contrast to its closest strucꢀ
(
3
EI mode: source temperature 200°С, 70 eV; and MS in
tural analogue
nantly gives dimers under the same conditions [20,
1]. It is seen from the presented results that the activꢀ
α
ꢀmethylstyrene, which predomiꢀ
+
Cl mode: source temperature 150°С, methane as the
reagent gas. The EI mass spectra of the styrene dimers,
2
m
/
z
(intensity): transꢀ1,3ꢀdiphenylbutꢀ1ꢀene (Ia)—
ity of the catalysts in the reaction increases in the
order: Y < Beta < ZSMꢀ12.
Ik 1795: 209 (11.6); 208 (64.6); 193 (62.8); 178 (30.9);
1
1
1
30 (23.8); 115 (100); 91 (37.7); cisꢀ1,3ꢀdiphenylbutꢀ
ꢀene (Ib)—Ik 1687: 209 (8.1); 208 (44.6); 193 (50.1);
78 (26.5); 130 (23.9); 115 (100); 91 (39.3); cisꢀ1ꢀ
Zeolite Y promotes the formation of an oligomeric
product having a bimodal MMD. In the lowꢀmolecuꢀ
lar part (oligomerization degree n = 2–5), the styrene
dimers prevail, whereas the highꢀmolecular fraction
contains oligomers with a molecular weight of 1510.
The yield of these oligomers increases with a decrease
in the temperature from 110 to 80°С or in the catalyst
concentration from 10 to 5 wt %.
The oligomers prepared in the presence of the
highꢀsilica zeolites Beta and ZSMꢀ12 are characterꢀ
ized by a narrower MMD (n = 2–5 and 2–4, respecꢀ
tively), the percentage of the dimers in them increases
to 69–79.3 wt %.
It should be noted that in the presence of zeolites Y
and Beta, the transꢀisomer of 1,3ꢀdiphenylbutꢀ1ꢀene
methylꢀ3ꢀphenylindane (IIa)—Ik 1702: 209 (15.1);
08 (85.3); 207 (17.9); 193 (56.9); 178 (39.7); 130
2
(
(
(
100); 115 (75.8); transꢀ1ꢀmethylꢀ3ꢀphenylindane
IIb)—Ik 1719: 209 (18.1); 208 (100); 207 (25.5); 193
+
69.6); 178 (47.0); 130 (85.5); 115 (80.8). The Сl
massꢀspectra of the styrene dimers,
Ia—Ik 1795: 209 (33.82); 208 (12.39); 207 (3.25);
Ib—Ik 1687: 209 (1.38); 208 (5.14); 207 (1.37); IIa
Ik 1702: 209 (4.03); 208 (7.02); 207 (7.31); IIb—Ik
719: 209 (4.68); 208 (7.97); 207 (8.02). It is known
m/z (intensity):
—
1
that when both of the isomers are present, the mass
spectra of the cisꢀ and transꢀisomers can be distinꢀ
guished: as a rule, the molecular ion is more abundant
in the spectrum of the transꢀisomer [17]. The influꢀ
(
Ia) was mostly obtained; only traces of the cisꢀisomer
(Ib) of the linear dimer were present. On zeolite ZSMꢀ12,
ence of alkene stereochemistry on the abundance of
+
the amount of the cisꢀisomer (Ib) reached 10 wt %.
(
М + Н) ions is most clearly displayed in chemical
+
ionization (Сl ) mass spectra. The peaks of these ions
The comparison of the isomeric composition of the
are more intensive for transꢀisomers than for cisꢀisoꢀ dimers obtained in the presence of different zeolites
mers [18].
shows that the ratio between the cyclic and linear isoꢀ
mers II changes towards an increase in the amount
:
I
The MMD of the styrene oligomers was deterꢀ
mined by HPLC analysis with an HPꢀ1090 chromatoꢀ
graph fitted with the polystyrene column PI gel 100
and a refractive index detector; toluene flow rate
of linear dimers on passing from zeolite Y to zeolite
ZSMꢀ12, i.e., with a decrease of the crystal lattice pore
size.
The results of styrene oligomerization in a solvent
chlorobenzene) at various initial concentrations of
Å
–1
0.8 ml/min, recorder speed 1.5 cm .
(
For calibration, the styrene dimers and trimers the monomer [М]0 are presented in Fig. 1. It has been
were isolated by vacuum distillation. Their molecular found that, as in the experiments without a solvent,
weights as well as the molecular weights of oligomers zeolites ZSMꢀ12 and Beta exhibit the highest activity.
with a polymerization degree of
mined by Rast’s method [19]. The other
n
= 14 were deterꢀ The activity of the zeolite Y is considerably lower
ꢀmers were (Fig. 1a). A decrease in the initial monomer concenꢀ
n
PETROLEUM CHEMISTRY Vol. 50
No. 2
2010

STYRENE OLIGOMERIZATION CATALYZED BY ZEOLITES
(а) Selectivity, % (b) Selectivity, %
131
Styrene conversion, wt %
00
(c)
1
3
2
8
0
0
0
0
3*
2
*
6
2
3
1
1
'
1
1
**
*
4
2
3'
2'
2**
3**
1
0
2
4
6
8
10 0
2
4
6
8
10 0
2
4
6
8
10
M] , mol/l
[
0
Fig. 1. Influence of the initial styrene concentration [М]0 on (a) styrene conversion, (b) selectivity for dimers and oligomers, and
c) selectivity for linear and cyclic dimers in the presence of zeolites ( ) Y, ( ) Beta, and ( ) ZSMꢀ12; reaction conditions: 20 wt %
of catalyst, 110°С, 1 h. ( ) Linear dimers, ( ') cyclic dimers, ( *) total dimers, and ( ** **) oligomers.
(
1
2
3
3
1
⎯
3
1
'
⎯
3
1*
⎯
1
⎯3
tration [М]0 in chlorobenzene from 8.8 to 0.88 mol/l
Studying styrene polymerization in dichloroethane
leads to an increase in the styrene conversion. The in the presence of H SO4, Jenkinson and Pepper [22]
2
influence of the abovementioned factor on the rate of found that the addition of tertꢀbutanol led to the terꢀ
styrene oligomerization is particularly noticeable in mination of oligomer chains, resulting in products
the presence of zeolite Y.
with smaller molecular masses. We have tried to use
this approach in order to increase the dimer formation
selectivity in the presence of zeolite Y. It has been
found that the admixture of 0.5 wt % tertꢀbutanol leads
to an increase in the selectivity for the linear dimer—
The styrene oligomerization catalyzed by zeolite Y
in the solvent gives mostly dimers and trimers (83–
9
n
2
5 wt %), the maximal degree of oligomerization is
= 5, but the amount of pentamers does not exceed
%. The total yield of dimers increases from 47 to 64%
the Іa
: ІІ ratio changes from 63 : 37 (without alcohol)
to 70 : 30 (20 wt % of the catalyst, 110°С, [М]0
=
with a decrease in the monomer concentration [М]0
and the proportion of linear dimers among them
increases from 51 to 56 wt % (Figs. 1b, 1c).
2.2 mol/l). In addition, the MMD of oligomers narꢀ
rows: the products contain only dimers and trimers. At
the same time, the styrene conversion drops by 30%
and side products appear, which are codimers of styꢀ
rene and isobutylene formed as a result of the alcohol
dehydration.
The investigation into the influence of the catalyst
concentration and temperature on the styrene converꢀ
sion and composition of oligomers has shown
A similar dependence has been obtained for zeolite
Beta, although the dimer formation selectivity and, in
particular, that of the linear isomer is higher: 67–75 wt %
for dimers and 58–66 wt % for the linear isomer Ia
(
Figs. 1b, 1c).
A decrease in the initial monomer concentration (Table 2) that a high monomer conversion (90–99%)
М]0 in chlorobenzene from 8.8 to 0.8 mol/l has a negꢀ is reached at 100–110°С over zeolites Beta and
[
ligible influence on the styrene conversion in the presꢀ ZSMꢀ12 taken in an amount of 10–20%. Under the
ence of zeolite ZSMꢀ12 as well as on the oligomer same conditions, zeolite Y is less active: the styrene
composition. Thus, the styrene conversion increases conversion over it does not exceed 60 wt %.
from 90 to 99% (Fig. 1a) and the amount of dimers
and oligomers with remains almost unchanged have a considerable effect on the constitution of the
Fig. 1b). The isomeric composition of the dimers is oligomers. With an increase in the temperature and
The change in the reaction parameters does not
n
≥
3
(
changed: with a decrease in the concentration [М]0 in catalyst concentration, the rate of the intramolecular
chlorobenzene, the linear dimer formation selectivity alkylation rises and, as a result, the selectivity for linꢀ
increases (from 55% at [М]0 = 8.8 mol/l to 78% at ear dimers decreases whereas that for the cyclic dimers
[М]0 = 0.88 mol/l) (Fig. 1c).
increases (Figs. 2a, 2b).
PETROLEUM CHEMISTRY Vol. 50
No. 2
2010

132
GRIGOR’EVA et al.
Table 2. Influence of the catalyst concentration and reaction temperature on the styrene conversion and product composition
(
[M] = 2.2 mol/l, 1 h)
0
Reaction conditions
Oligomer composition, wt %
= 3
Styrene converꢀ
sion, wt %
Catalyst
[
kt], wt %
10
T
,
°
C
n
= 2
n
n
= 4, 5
Y
110
90
53.9
39.8
59.6
68.2
63.4
64.8
93.7
51.3
91.6
96.0
45.7
83.8
41.4
91.4
98.3
99.1
99.5
66.4
64.1
62.5
63.3
56.5
70.4
72.1
71.6
72.3
71.8
85.2
83.3
81.7
83.8
83.2
81.7
81.6
22.8
25.8
31.2
27.6
32.6
24.1
24.4
22.4
23.1
25.2
11.8
14.9
15.3
13.7
14.7
16.3
16.3
10.8
10.1
6.3
8.1
10.9
5.5
3.5
6.0
4.6
3.0
3.0
1.8
3.0
2.5
2.1
2.0
2.1
20
20
20
30
5
0
0
110
120
110
110
110
80
Beta
ZSMꢀ12
1
2
1
1
00
10
5
0
0
110
110
80
1
2
90
1
1
10
20
30
110
To explain the results obtained, let us consider the types with strengths of 1189 and 1265 kJ/mol are
acid properties of the zeolites as well as their structural present. The BAS concentration in the samples of zeoꢀ
characteristics. According to the data presented in lites Beta and ZSMꢀ12 [21] is considerably lower than
Fig. 3 [20], the concentration of Brönsted acid sites in zeolite Y; however, the strength of the acid sites is
(
BAS) is maximal in the zeolite Y sample. The higher, 1165 kJ/mol. Note the high concentration of
strength of the structural OH groups located in large Lewis acid sites (LAS) in zeolite Beta, since it is
cavities of the zeolite is 1170 kJ/mol on the PA scale. known that they can transform into BAS in the reacꢀ
In addition, the acidic AlOH groups of two different tion with water [23].
Selectivity, %
00
(а)
(b)
1
100
80
60
40
20
0
80
60
40
20
3
2
3
2
1
1
1'
1'
2'
2'
3'
3'
0
10
20
[
30 70 80 90 100 110 120
kt], wt %
T, C
°
Fig. 2. Influence of (a) the catalyst concentration and (b) reaction temperature on the dimer formation selectivity in the presence
of zeolites ( ) Y, ( ) Beta, and ( ) ZSMꢀ12; reaction conditions: (a) 110°C, 1 h; (b) 20 wt % of catalyst, 1 h. ( ) Linear dimers
and ( ') cyclic dimers.
1
2
3
1⎯3
1 '⎯3
PETROLEUM CHEMISTRY Vol. 50
No. 2
2010

STYRENE OLIGOMERIZATION CATALYZED BY ZEOLITES
133
Cн+,
mol/g
0.55
quence, the reaction gives mostly linear styrene dimers
Ia Ib).
It was found that both the activity and selectivity of
zeolites in the styrene oligomerization are strongly
dependent on the structure type of the zeolite. For the
synthesis of the styrene linear dimers, the use of zeolite
×
0.62 nm in zeolite ZSMꢀ12) [24]. As a conseꢀ
µ
500
400
300
200
100
0
(
,
ZSMꢀ12 is most favorable (
00 wt %). Zeolite Beta is close to zeolite ZSMꢀ12 by
activity and gives dimers as the main products (70–
0%), mostly the linear isomer Ia. In the presence of
S = 82%, conversion 98–
1
8
the least active zeolite Y, styrene affords a complex
mixture of oligomers in which dimers (53–60% in
chlorobenzene) or dimers and trimers (60–80% in
bulk) are predominant.
Y
Beta
ZSMꢀ12
ACKNOWLEDGMENTS
The work was supported by the Russian Academy
of Sciences under the General Chemistry and Materiꢀ
als Science Division program no. 8 “The Developꢀ
ment of Scientific Principles of New Chemical Techꢀ
nologies Including the Production of Pilot Batches of
Substances and Materials.”
Fig. 3. Acid properties of zeolites Y, Beta, and ZSMꢀ12.
BAS is the total concentration of Brönsted acid sites;
LAS is the total concentration of Lewis acid sites; OH str.
are structural OH groups in the cavities of zeolite Y;
OH chan. are structural OH groups in the channels of the
zeolites Beta and ZSMꢀ12; OH surf. are surface acidic
OH groups.
Σ
REFERENCES
As the styrene dimerization proceeds via the catꢀ
1
2
3
4
5
. B. B. Corson, J. Dorsky, J. E. Nikels, et al., J. Org.
Chem. 19, 17 (1954).
. B. B. Corson, W. J. Heintrelman, H. Moe, and
C. R. Roussean, J. Org. Chem. 27, 1636 (1962).
. T. Higashimura, M. Hiza, and H. Hasegawa, Macroꢀ
molecules 12 (2), 217 (1979).
. A. R. Taylor, G. W. Keen, and E. J. Eisenbraun, J. Org.
Chem. 42 (22), 3477 (1977).
ionic oligomerization mechanism, an increase in the
Brönsted acidity of the catalyst must lead to an
increase in its activity. Therefore, a maximal styrene
conversion is expected in the presence of zeolites Y
and Beta. Indeed, zeolite Beta displays a high activity
in the reaction; however, a low styrene conversion is
observed in the presence of zeolite Y. Probably, this is
due to the crystal lattice structure of zeolite Y for
which the diameter of the large cavity (1.2 nm) is more
than that of the entrance window (0.8 nm) [24]. If the
size of the molecules resulting from the oligomerizaꢀ
tion in the large cavity is more than the diameter of the
entrance window, they remain in the cavity. Thus, the
main part of BAS located in large cavities of zeolite Y
is very quickly deactivated and the reaction is cataꢀ
lyzed by a small number of surface acid centers. As a
. US Patent No. 4254292 (1981).
6. US Patent No. 4442027 (1984).
7
. K. Thinius, Chemie, Physik, und Technologie der Weichꢀ
macher, (Leipzig, 1963; Khimiya, Moscow, 1964).
8
. US Patent No. 20060069212 (2006).
. US Patent No. 20040242441 (2004).
9
10. RU Patent No. 2142486 (1999).
consequence, the bulk oligomerization of styrene proꢀ 11. M. Sawamoto, T. Masuda, H. Nishii, and T. Higashiꢀ
ceeds with a low monomer conversion and yields a
large amount of highꢀmolecularꢀmass oligomers.
When the oligomerization is carried out in a solꢀ
vent, the styrene concentration in zeolite pores 13. T. Hamaya and S. Yamada, Makromol. Chem. Rapid
mura, J. Polym. Sci.: Polym. Lett. 13, 279 (1975).
12. T. Higashimura and H. Nishii, J. Polym. Sci., Part A:
Polym. Chem. 5, 329 (1977).
Commun.
). In addiꢀ 14. K. B. Yoon, J. L. Lim, and J. K. Kochi, J. Mol. Cat. 52
375 (1989).
1, 379 (1980).
becomes lower, thereby reducing the possibility of the
formation of large oligomer molecules (
tion, the solvent accelerates the diffusion of the prodꢀ
ucts from zeolite pores. As a result, the styrene converꢀ
sion increases and the molecularꢀmass distribution of
oligomers narrows.
n
≥
3
,
1
1
1
5. A. Benito, A. Corma, H. Harcia, and J. Primo, Appl.
Catal., A 116, 127 (1994).
6. M. L. Pavlov, M. I. Levinbuk, E. M. Savin, et al., RU
Patent No. 2090502 (1997).
For the reactions catalyzed by zeolites Beta and
ZSMꢀ12, the size of the resulting oligomers is limited
by the diameter of the narrower straight channels
7. A. T. Lebedev, Mass Spectrometry in Organic Chemistry
(BINOM. Laboratoriya znanii, Moscow, 2003) [in
Russian].
(
0.55
×
0.55 and 0.64
×
0.75 nm in zeolite Beta and
PETROLEUM CHEMISTRY Vol. 50
No. 2
2010

134
GRIGOR’EVA et al.
1
8. MassꢀSpectral Analysis of Mixtures with the Use of Ionꢀ 21. N. G. Grigor’eva, R. R. Galyautdinova, E. A. Paukshꢀ
Molecule Reactions, Ed. by A. A. Polyakova (Khimiya, tis, et al., Neftekhimiya 46, 1 (2006) [Pet. Chem. 46
Moscow, 1989) [in Russian]. 332 (2006)].
,
1
9. A. J. Gordon and R. A. Ford, The Chemist’s Companion: 22. D. H. Jenkinson and D. C. Pepper, Proc. R. Soc. Lonꢀ
A Handbook of Practical Data, Techniques and Referꢀ
don A263 82 (1961).
ences (Wiley, New York, 1972; Mir, Moscow, 1976).
23. K. G. Ione, Polyfunctional Catalysis on Zeolites (Nauka,
Novosibirsk, 1982) [in Russian].
20. N. G. Grigor’eva, E. A. Paukshtis, B. I. Kutepov, et al.,
Neftekhimiya 45, 453 (2005) [Pet. Chem. 45, 419 24. W. M. Meier, Atlas of Zeolite Structure Types, Ed by
2005)]. W. M. Meier, D. H. Olson, and Ch. Baerlocher (1996).
(
PETROLEUM CHEMISTRY Vol. 50
No. 2
2010