Ethylene to Propylene over Zeolite ZSM-5: Improved Catalyst Performance by Treatment with CuO

Article abstract of DOI:10.1134/S1070427219070085

The ZSM-5 zeolite base was applied to produce light olefins in the process of converting ethylene to propylene, as well as copper oxide to improve the catalyst. After loading the copper oxide by inoculation, the modified catalyst was evluated for accurate determination of the specification via XRD, SEM, BET, and FTIR analyzes. The activity of this catalyst was evaluated in the process of ethylene to propylene conversion in a constant reactor at 400°C, 1 atm, and 0.5 cc/min of pure ethylene. The modified catalyst of selectivity of ethylene and propylene increased as the temperature rose and the maximum selectivity table at 400°C was achieved.

Full text of DOI:10.1134/S1070427219070085

ISSN 1070-4272, Russian Journal of Applied Chemistry, 2019, Vol. 92, No. 7, pp. 933−939. © Pleiades Publishing, Ltd., 2019.
CATALYSIS
Ethylene to Propylene over Zeolite ZSM-5: Improved Catalyst
Performance by Treatment with CuO
Ehsan Kianfara,b,*
a
Department of Chemical Engineering, Arak Branch, Islamic Azad University, Arak, Iran
b
Young Researchers and Elite Club, Gachsaran Branch, Islamic Azad University, Gachsaran, Iran
*
e-mail: e-kianfar94@iau-arak.ac.ir
Received January 30, 2019; revised May 20, 2019; accepted June 26, 2019
Abstract—In this paper, the ZSM-5 zeolite base is used to produce light olefins in the process of converting
ethylene to propylene, as well as copper oxide to improve the catalyst. After loading the copper oxide by inocula-
tion, the modified catalyst was investigated for accurate determination of the specification by XRD, SEM, BET,
and FTIR analyzes. The activity of this catalyst was evaluated in the process of ethylene to propylene conver-
sion in a constant reactor under operational conditions (temperature 400°C, pressure 1 atm, and feed flow rate of
–
1
0
.5 cc min of pure ethylene), which also shows the results of tests of catalyst activity evaluation The modified
catalyst of selectivity of ethylene and propylene will increase as the temperature rises and the maximum selectiv-
ity table at 400°C will be achieved.
Keywords: ethylene to propylene process, fixed-bed reactor, ZSM-5 catalyst
DOI: 10.1134/S1070427219070085
INTRODUCTION
low solvent dosage of solid phase extraction, but also
acquire the excellent property of specific recognition
of molecularly imprinted polymers [4–6]. Presently,
some research groups have studied the preparations and
applications of quercetin molecularly imprinted polymers
[7–9]. Pakade et al. [10] have synthesized MIP with the
bulk polymerization method using quercetin as template
molecule, and established the MISPE method to enrich
and separate the quercetin in horseradish tree leaf, flower,
kaempferol and other flavonoids. The recovery result was
good and the recovery rate was 75–86%.
Since the synthetic drugs are not easily absorbed by
human body and have certain toxic and side effect, people
prefer to extract the medicinal ingredients from plants.
Flavonoids are a kind of natural substances which are
widely present in plants and have important medicinal
values. In recent years, the study of flavonoids has been
inclined to focus on the applied study of extraction and
separation process. The method of extracting quercetin,
one of the main constituents of flavonoids, is also
being studied and improved [1, 2]. At present, the main
extraction methods are: organic solvent extraction,
ultrasonic extraction, enzyme extraction, supercritical
fluid extraction, macroporous resin adsorbing method and
so on, but all of them are flawed by cumbersome process,
high equipment cost, poor purity and other problems to
some extent [3].
Reversible addition-fragmentation chain transfer
free radical polymerization (RAFT) is a widely used
active/controllable free radical technology, which can
control the structure and property of polymers [11, 12].
Reversible addition-fragmentation chain transfer free
radical polymerization combined with precipitation
polymerization method (RAFTPP), through the control of
reaction speed, is able to obtain the imprinted microsphere
with a uniform particle size and good dispersity, so that it
can be more widely used [13, 14]. The aim of this paper is
to use RAFTPPmethod to prepare quercetin molecularly
The application of molecularly imprinted solid phase
extraction (MISPE) in the separation and purification
of the effective constituents in plant samples has not
only retain the advantages of simple operation and
9
33

934
EHSAN KIANFAR
Others Acrylonitrile
Cracking (FCC) and Thermal Cracking of Ethan are
classified as the methods with low efficiency [15–
0]. The steam cracking process is implemented in a
temperature of about 800–880°C and nearly 40% of
energy is consumed by all of the petrochemical industries
Acrylic acid
11%
7%
4
%
Cumene
2
Propanol 2%
Propylene
oxide 7%
6
%
with high emissions of CO , what the development
2
of advanced techniques not only results in minimized
energy consumption but also decreases emissions
of CO . This concern can be important to protect the
2
environment [20–25]. In addition, according to limited
P/E (propylene to ethylene) ration control in steam
cracking process where olefins are directly depended
on the feed type and also the higher growth of global
demand for propylene compared to ethylene [26, 27].
Studies indicate that, according to increase demand for
propylene in the global market, it makes sense to find
alternative methods for propylene production. [28]. It is
well understood that low numbers of Brønsted acid sites
leads to higher selectivity to light olefins in conversion
of methanol to hydrocarbons . Observed that an increase
in Si/Al in the ZSM-5 zeolite framework leads to a
pronounced decrease in total acidity of the zeolite and
consequently in acidic site density. Studied the effect of
acidity on product selectivity in conversion of methanol
Polypropylene
3%
6
Fig. 1. (Color online) Products of propylene [5].
INTRODUCTION
Lightolefins(ethyleneandpropylene), areconsidered
among the most crucial elements in petrochemical
industries, which are used for producing polymers and
diverse chemicals. As the main feed of petrochemical
processes, propylene is widely used [1–3]. Figure
to hydrocarbon, by changing the SiO /Al O ratio from
1
shows the percentage of using propylene for each
2
2
3
3
5 to 1670 in ZSM-5 zeolite. They observed that by
production: 63% is used for polypropylene, 7% is used
for acrylonitrile, 7% is used for propylene oxide, 6%
is used for cumene, 4% is used for acrylic acid, 2% is
used for isopropanol and 11% used for production of
other chemicals [4, 5]. Olefins can be produced through
diverse processes and different raw materials. The
common point of all these processes is production in a
wide range of products and production of peripherals.
In addition to mentioned industrial processes, there
exist additional non-industrial technologies in diverse
development steps including oxidative coupling of
methane (OCM), propane dehydrogenation (PDH)
for production of propylene, low-value heavy olefins
cracking exemplary C4/C5, metathesis of ethylene and
butylene to propylene and conversion of methanol to
light olefins (MTP, MTO) [6–10]. Concerning access
to hydrocarbon resources in different countries, diverse
strategies are selected for production of olefins so that
upon discovery of such strategies, propylene to ethylene
ratio has been considerably decreased in steam cracking
units and this has resulted in complicated propylene
market [11–14]. Although Thermal Cracking of
Naphtha is the main process of light olefins production
such as propylene, such technologies as Fluid Catalytic
increasing this ratio, the selectivity to C2/C5 olefins is
increased. [22]. Zeolites as catalysts have many unique
properties such as acidity, shape-selectivity, high surface
area and structural stability. The destination of this article
is using the ZSM-5 catalytic process for producing
light olefins. This works destination is synthesized and
specify characteristics of CuO/ZSM-5 study and assess
the role of this catalyst in ethylene to propylene process.
In doing so, direct conversion of ethylene to propylene
may be an efficient way to be responsive global demand.
Here, ethylene was used as a feed. Also, insemination
of modified zeolite by CuO caused to reach a propylene
with higher conversion rate and selectivity. The catalyst
with 5 wt. % copper oxide has the highest conversion
rate and better selectivity than other percentages.
MATERIALS AND METHODS
Materials
Sodium aluminate (technical grade) was purchased
Riedel-deHaen. Silicic acid (96.6%), tetrapropylam-
monium bromide (98%), copper (II) nitrate (99.9%),
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 92 No. 7 2019

ETHYLENE TO PROPYLENE OVER ZEOLITE ZSM-5
935
sodium hydroxide (97.5%), methanol (99.9%), ethanol
96%), ammonium nitrate (99.95%) was supplied by
Merck.
After impregnation, the solution dried at 110°C for 24 h
and calcined at 550°C under air flow. In this step, the
catalyst is synthesized by the conventional impregnation
method. Next, the catalyst shaped cylindrically to be
used for performance tests in the reactor.
(
METHOD AND PROCEDURE
Zeolite ZSM-5 Catalyst Synthesis
Experimental Setup
Initially the desired amount of sodium aluminate
was added to hydroxide sodium solution and stirred
for 60 min (solution A). In another beaker, required
amount of tetra-propyl-ammonium bromide was added
to sodium hydroxide solution and stirred for 30 min.
Silicic acid and deionised water were slowly added and
stirred for another 30 min (solution B). Subsequently,
solution A was mixed with solution B and stirred for 60
min. Final gel was transferred to a Teflon-lined stainless
steel autoclave and heated at 180°C for 12 h. Finally,
contents of reactor were filtered, washed and dried at
temperature 110°C for 12 h. The solid product was
calcined at 500°C for 5 h. Ion exchanging of ZSM-5
zeolite performed using ammonium nitrate solution
Figure 2 shows a scheme of the experimental system.
After studying structural specifications of synthesized
catalyst, ethylene to propylene low-pressure pilot was
used to evaluate their activity and performance over the
process. A pilot was designed and made for the catalytic
conversion of ethylene to propylene. In this pilot, liquid
and gas were able to be injected concurrently and a
precise system of temperature control was considered
for micro-reactor and electric oven. Such features as
adjustability and flow rate control of gas and liquid flows
are provided by the pilot to make diverse detention times
of ethylene. For efficiency assessment of synthesized
catalysts of ethylene to propylene process, such
parameters as catalyst amount and flow rate of input
feed were kept 1.2 g and 0.5 cc min , respectively. Also,
ethylene to propylene reaction was accomplished in a
fixed-bed reactor with stainless steel materials, length of
500 mm, the internal diameter of 7 mm in a temperature
of 400°C and pressure of 1 atm. The low-nitrogen
flow was used for better distribution and prevention of
evaporated ethylene backflow. In ethylene to propylene
process, the value of output liquid hydrocarbons from
micro-reactor was measured in percentage to assess
the type of the produced hydrocarbons by Varian gas
chromatography (Model CP-3800 made in the US). The
used gas chromatography device in the present study
had FID indicator and the column used in this device
–
1
(1 M). Zeolite was mixed with solution and heated at
110°C for 6 h. In following step, silica foam was added
to the solution while mixing. After 24 h of mixing, the
derived gel was poured into an autoclave reactor and
heated at 150°C for 6 days. Catalyst was dried at 110°C
for 12 h and calcined at 500°C for 5 h [27, 22].
Method of CuO/ZSM-5 Catalyst Synthesis
First of all, Cu precursor dissolved in appropriate
ratios in water and pH of the solution controlled by
NH . In next step, impregnation was done by mixing
3
support with the obtained solution in the previous step.
Condenser
Gas chromatograph (GC)
N2
Liquid products
Reactor
Ethylene
MFC
Preheater
Fig. 2. Experimental system for evaluation of ZSM-5 catalyst synthesis performance for ethylene to propylene conversion.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 92 No. 7 2019

9
36
Table 1. Physicochemical properties of different zeolite samples
Catalyst Si/AL SiO /Al O
ZSM-5
EHSAN KIANFAR
Crystal size,
nm
BET surface area,
Pore volume,
2
2
3
2
‒1
3
‒1
m g
cm g
15
12
11
30
17
28
30
300
280
254
245
230
0.39
0.36
0.33
0.32
0.30
24
22
CuO/ ZSM-5(5%)
CuO/ ZSM-5 (7%)
CuO/ ZSM-5 (9%)
CuO/ ZSM-5 (11%)
1
0
20
18
32
34
9
was Petrocol DH with a length of 60 m and diameter of
D = K/(β cos θ).
(1)
0
.25 mm. Helium was used as carrier gas.
In this formula, λ is the wavelength of X-ray and D
is mean size or thickness of the crystal perpendicular to
the diffraction plane. K is the constant of the equation
and depends on crystalline system and also selection
of integral width or Full Width at Half Maximum
RESULTS AND DISCUSSION
Characterization Results
(FWHM). This constant is about 0.9. β is the angle
XRD analysis. Figure 3 indicates the spectra
width or Full Width at Half Maximum (FWHM) and
is calculated in radian. θ is the peak angle in degrees.
Crystal size for different samples have been calculated
using Scherrer equation and been presented in Table 1.
After impregnation, crystal size of ZSM-5 zeolite has
been increased from 17 nm to 34 nm for zeolite loaded
with 5 and 11% CuO, respectively.
associated with XRD analysis for Zeolite ZSM-5. As
it can be seen, the spectrum has some prominent peaks
associated with Zeolite ZSM-5. The relative crystalline
mode of this catalyst was calculated according to a
reference, considering prominent peaks angles of 22–
2
5°. The comparison of X-Ray Diffraction data from
produced Zeolite sample shows crystalline phase of
ZSM-5 in crystal structure. Debye-Scherer equation is
used for calculation of mean crystal size of particles
FTIR analysis. Spectrum of molecular vibrations
is considered as a unique specification and describes
features of a molecule. In fundamental and simple
terms, infrared spectrum is known as result absorption
of electromagnetic radiation in the frequencies which
show a relation with vibration of specific sets to chemical
bonds from inside the molecule. Therefore, description
of IR spectrum encompasses relation and correlation
of frequencies for all types of bonds [23]. Vibrational
frequencies can be divided into two wide groups: group
frequencies and fingerprint frequencies. The former
(μm) which is defined as follows:
8
000
000
000
000
000
000
000
000
0
7
1
6
5
4
3
2
1
2
3
explains group specifications of atoms (e.g. –CH and
3
4
5
–OH) and helps for characterization and description of
a compound. However, the latter describes excellent
specifications of specific molecule. Combination of the
bonds which are along with both group and fingerprint
frequencies is used to determine a specific composition
1
0
20
30
40
50
60
70
80
[24]. Figure 4 shows FTIR spectroscopy analysis for
Zeolite ZSM-5. In FTIR spectrum, zeolites are seen
in two peak categories. The first category is dedicated
Fig. 3. (Color online) XRD pattern for prepared catalyst.
1) CUO/ZSM-5 (11%), (2) CUO/ZSM-5 (9%), (3) CUO/
(
ZSM-5 (7%), (4) CUO/ZSM-5 (5%), (5) ZSM-5. The
to internal vibrations of TO (i.e. primary unit of the
4
same for Fig. 4.
structure). T means the element inside Zeolite structure
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 92 No. 7 2019

ETHYLENE TO PROPYLENE OVER ZEOLITE ZSM-5
937
–
1
3
2
2
1
1
0
5
0
5
0
5
0
hydroxyls and the link 3432 cm is corresponded to the
functional group AL–OH.
1
2
3
SEM analysis. Figure 5 shows SEM analysis results
for calcined catalyst which were photographed with a
zooming of 10. As it can be seen from micro-graph, the
sample crystals have a suitable dispersion and regular
morphology. These results are in a good agreement with
the crystalline size achieved by XRD data. The SEM
photographs of calcined and CuO impregnated ZSM-
4
5
5
catalysts also show that the particles are spherical in
shape. Typical SEM images of ZSM-5 and CuO/ZSM-5
are shown in Fig. 5. There was no the significant change
in the crystal morphology after CuO loading.
0
1000
2000
3000
4000
Fig. 4. FTIR analysis pattern results for prepared catalyst.
BET analysis. Table 2 present physical and chemical
properties of catalyst ZSM-5 and CuO/ ZSM-5 obtained
by using BET analysis. Also, BET analysis was conduct-
ed to be informed of specific surface area, size and vol-
ume of pores. Specific surface area of the catalyst of CuO/
which is linked to oxygen (e.g. Si and Al). These peaks
–
1
are typically in the 950–1250 and 420–500 cm area
which are attributed to T–O and O–T–O stretching
vibrations, respectively. The second category contains
the vibrations associated with tetrahedral connections.
The first observed seen ones frjom the second category
2
ZSM-5 was decreased from 300 to 200 m /g by increas-
ing copper oxide from 0 to 11 wt %. Also, total pores vol-
3
ume was decreased from 0.39 to 0.30 cm /g by increasing
–
1
copper oxide from 0 to 11 wt %, as well. The results show
that zeolite ZSM-5 retains its MFI structure by adding up
to 11% by weight of copper oxide, and the structure still
has acceptable crystallinity. Amin et al. Have claimed that
by reducing the size of the crystal, the structure of the
network has a greater defect, and this shortage of the net-
work has reduced peak intensity [25–31].
are appeared in the 500–600 and 1300–1700 cm area.
Zooming FTIR spectrum in Fig. 4, we can precisely
–
1
investigate absorbance compositions around 3400 cm
which are associated with hydroxide link. As it can be
seen from this Fig. 4, this spectrum contains 3 peaks
around stretching area of OH group within wave
–
1
numbers of 3432, 3610, and 3732 cm . The observed
–
1
link in 3732 cm is associated with Silanol (Si–OH)
Effect of temperature on rate of ethylene
conversion by CuO/ ZSM-5. Figure 6 present effect
–
1
group and 3610 cm is correlated with acidic zeolite
CUO/ZSM-5 (5%)
ZSM-5
CUO/ZSM-5 (7%)
CUO/ZSM-5 (9%)
CUO/ZSM-5 (11%)
Fig. 5. SEM analysis for prepared catalyst.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 92 No. 7 2019

938
EHSAN KIANFAR
Table 2. BET results for different synthesized catalysts
8
6
4
2
0
0
0
0
0
BET
Pore
Catalyst
surface
area, m g
volume,
cm g
2
‒1
3
‒1
ZSM-5
300
265
254
204
200
0.39
0.36
0.33
0.31
0.30
CuO (5%) / ZSM-5
CuO (7%) / ZSM-5
CuO (9%) / ZSM-5
CuO (11%) / ZSM-5
0
100
200
300
400
T, °C
5
%
7% 9% 11%
copper oxide has a better selectivity than other percent-
ages.
Fig. 6. (Color online) Ethylene conversion rates in terms of
temperature using CuO/ZSM-5.
CONCLUSIONS
3
2
1
5
5
5
5
In this article, zeolite ZSM-5 was used as the catalytic
base for production of light olefins. Also, the copper
oxide was employed to improve the performance of
the catalyst. The results of catalytic cracking using the
mentioned catalyst showed increased selectivity of light
olefin versus thermal cracking at diverse temperatures.
The analyses XRD, BET, FTIR, and SEM were
conducted on some of the modified samples and the
results showed that the catalyst structure was kept intact
following adding copper oxide. The results indicated
that the selectivity of ethylene and propylene on the
catalyst with modified metal of copper oxide would
have an ascending trend by increasing the temperature
and the maximal selectivity will be obtained at 400°C.
0
100
200
T, °C
7% 9% 11%
300
400
5
%
Fig. 7. (Color online) Selectivity of propylene rates in terms of
temperature using CuO/ZSM-5.
of temperature on ethylene to propylene conversion
rate at diverse temperatures on the ZSM-5 catalysts
modified by copper oxide. Figure 6 show conversion
rate of ethylene according to temperature using CuO/
ZSM-5 catalysts with 5, 7, 9, and 11 wt %. As it can be
seen from Fig. 6, ethylene conversion rate increases in
higher temperatures and the ascendant trend are seen.
Maximum and minimum conversion rates are seen at
NOMENCLATURE
T: temperature, °C.
id: internal diameter, mm.
–
1
F : molar flowrate of methanol, cc min .
A0
W: weight of catalyst, g.
4
00°C and 50°C, respectively. As can be seen in Fig. 6, a
REFERENCES
catalyst with 5 wt % copper oxide has a better conversion
than other percentages.
1
2
3
. Noyen, J.V., Wilde, A.D., Schroeven, M., et al., Int. J.
Appl. Ceramic Technology, 2012, vol. 9, pp. 902–910.
Effect of temperature on selectivity of propylene
with CUO/ ZSM-5 catalyst. Figure 7 presents impact of
temperature on the selectivity of propylene on the ZSM-
. Narula, C.K., Daw, C.S., Hoard, J.W., et al., Int. J. Appl.
Ceramic Technology, 2005, vol. 2, pp. 452–466.
5
catalysts modified by copper oxide. Figure 7 shows
. Singh, R.N., Int. J. Appl. Ceramic Technology, 2007,
vol. 4, pp. 134–144.
diagram of selectivity according to temperature, by us-
ing CuO/ZSM-5 catalysts with wt % of 5, 7, 9, and 11.
The effect of temperature on the selectivity of propylene
on copper oxide modified ZSM-5 catalysts is shown in
Fig. 7. As can be seen from Fig. 7, a catalyst with 5 wt %
4. Aghaei, E. and Haghighi, M., Microporous Mesoporous
Mater., 2014, vol. 196, pp. 179–190.
5. Amereh, M., Haghighi, M., Estifaee, P., Arabian J.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 92 No. 7 2019

ETHYLENE TO PROPYLENE OVER ZEOLITE ZSM-5
939
Chem., (In Press).
19. Nelson, H.C., Lussier, R.J., Still, M.E., Applied Catalysis,
983, vol. 7, pp. 113–121.
1
6
7
8
9
. Estifaee, P., Haghighi, M., Babaluo, A., et al., J. Power
Sources, 2015, vol. 257, pp. 364–373.
20. Bouvier, C., Reumkens, N., Buijs, W., J. Chromatography,
A, 2009, vol. 1216, pp. 6410–6416.
. Fathi, S., Sohrabi, M., and Falamaki, C., Fuel, 2014,
vol. 116, pp. 529–537.
21. Wang,Y., Xu, L.,Yu, Z., et al., Catalysis Communications,
2
008, vol. 9, pp. 1982–1986.
22. Zhang, K.F., J. Power Sources, 2006, vol. 162, pp. 1077–
081.
. Rahemi, N., Haghighi, M., Babaluo, A., et al., Int. J.
Energy Res., 2014, vol. 38, pp. 765–779.
1
. Brzozowski, R., Applied Catalysis A: General, 2004,
vol. 27, pp. 215–218.
23. Spahr, M.E., J. Electrochem. Soc., 1999, vol. 46,
pp. 2780–2783.
1
0. Gauthier, C., Chiche, B., Finiels, A., et al., J. Molecular
Catalysis, 1989, vol. 50, pp. 219–229.
24. Cañzares, P., Lucas, A.D., Dorado, F., et al., Appl. Catal.
A: Gen., 1998, p. 169.
11. Walendziewski, J. and Trawczyn, J., Ind. & Eng. Chem.
Res., 1996, vol. 35, pp. 3356–3361.
25. Donk, S.V., Janssen, A.H., Bitter, J.H., et al., Catal. Rev.,
1
1
1
1
2. Hathaway, P.E. and Davis, M.E., J. Catalysis, 1989,
2003, p. 45.
vol. 119, pp. 497–507.
26. Leach, E. and Bruce, E., Industrial Catalysis, 1983,
3. Sugi, Y., J. Chinese Chemical Soc., 2010, vol. 57,
vol. 1, New York: Academic Press, Inc.
pp. 1–13.
2
7. Jacobs, G. and Davis, B.H., In Catalysis, Spivey, J.J and
Dooley, K.M., Eds., Cambridge, The Royal Society of
Chemistry, 2007, p. 20.
4. Bouvier, C., Buijs, W., Gascon, J., et al., J. Catalysis,
2
010, vol. 270, pp. 60–66.
5. Kamalakar, G., Ramakrishna, M., Kulkarni, S.J., et al.,
Microporous & Mesoporous Materials, 2000, 38,
pp. 135–142.
28. Kianfar, E., Salimi, M., Pirouzfar, V., and Koohestani, B.,
Int. J. Appl. Ceramic Technology, 2017, vol. 15, no. 3,
pp. 734–741.
1
6. Kamalakar, G., Prasad, M.R., Kulkarni, S.J., et al.,
Microporous & Mesoporous Materials, 2002, vol. 52,
pp. 151–158.
29. Kianfar, E., Salimi, M., Pirouzfar, V., and Koohestani, B.,
Int. J. Chem. React. Eng., B, vol. 16, no. 7, pp. 1–7.
3
0. Kianfar, E., Salimi, M., Hajimirzaee, S., and
Koohestani, B., Int. J. Chem. React. Eng., 2018, https://
doi.org/10.1515/ijcre-2018-0127.
1
7. Addiego, W.P., Brundage, K.R., Glose, C.R., in Corning
Incorporated, 2005, New York: Corning, 244, 689 B2.
1
8. Campanati, M., Fornasari, G., and Vaccari, A., Catalysis
Today, 2003, vol. 77, pp. 299–314.
31. Kianfara, E., Russ. J. Appl. Chem., 2018, vol. 91, no. 10,
pp. 1710–1720.
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 92 No. 7 2019