Ethane Oxidation in the Presence of Copper-Containing Zirconia Modified with Acid Additives

Article abstract of DOI:10.1134/S0036024419110086

Abstract: The complete oxidation of ethane in the presence of catalysts containing 1, 3, and 5 wt % CuO deposited on four supports (zirconia, sulfated zirconia, tungstated zirconia, and La₂O₃-stabilized zirconia) is studied. The supports and the catalysts are characterized via BET, XRD, and thermal analysis. It is shown that 100% conversion of ethane is achieved even at a temperature of 300°C. It is found that the temperature of 100% conversion falls upon an increase in the copper content; the lowest temperature is obtained for catalysts based on unmodified zirconia. With respect to catalytic activity, the samples with the highest copper content are in the order 5%Cu/ZrO₂ > 5%Cu/5%La₂O₃/ZrO₂ > 5%Cu/15%WO₃/ZrO₂ > 5%Cu/5%SO₄/ZrO₂. The temperatures of 100% ethane conversion for these catalysts are 305, 385, 410, and 419°C, respectively.

Full text of DOI:10.1134/S0036024419110086

ISSN 0036-0244, Russian Journal of Physical Chemistry A, 2019, Vol. 93, No. 11, pp. 2140–2145. © Pleiades Publishing, Ltd., 2019.
Russian Text © The Author(s), 2019, published in Zhurnal Fizicheskoi Khimii, 2019, Vol. 93, No. 11, pp. 1661–1667.
CHEMICAL KINETICS
AND CATALYSIS
Ethane Oxidation in the Presence of Copper-Containing Zirconia
Modified with Acid Additives
P. A . D ony u sh a, A. L. Kustova,b,*, V. D. Nissenbaumb, A. L. Tarasovb, and L. M. Kustova,b
aDepartment of Chemistry, Moscow State University, Moscow, 119991 Russia
bZelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 119991 Russia
*e-mail: kyst@list.ru
Received November 1, 2018; revised March 8, 2019; accepted March 12, 2019
Abstract—The complete oxidation of ethane in the presence of catalysts containing 1, 3, and 5 wt % CuO
deposited on four supports (zirconia, sulfated zirconia, tungstated zirconia, and La2O3-stabilized zirconia) is
studied. The supports and the catalysts are characterized via BET, XRD, and thermal analysis. It is shown
that 100% conversion of ethane is achieved even at a temperature of 300°C. It is found that the temperature
of 100% conversion falls upon an increase in the copper content; the lowest temperature is obtained for cat-
alysts based on unmodified zirconia. With respect to catalytic activity, the samples with the highest copper
content are in the order 5%Cu/ZrO2
> 5%Cu/5%La2O3/ZrO2 > 5%Cu/15%WO3/ZrO2 >
5%Cu/5%SO4/ZrO2. The temperatures of 100% ethane conversion for these catalysts are 305, 385, 410, and
419°C, respectively.
Keywords: ethane oxidation, alkane oxidation, zirconia, sulfated zirconia, tungstated zirconia, copper oxide
DOI: 10.1134/S0036024419110086
INTRODUCTION
are used in this case. Oxides of copper, manganese,
iron, nickel, chromium, and cobalt are most com-
monly used in industry [9–12]. Metal oxide catalysts
are less active than noble metals, but they are charac-
terized by low cost and regenerability [3].
Volatile organic compounds (VOCs) constitute a
large group of organic substances that include halo-
gen-containing hydrocarbons, aldehydes, alcohols,
aromatic hydrocarbons, alkanes, alkenes, ketones,
ethers, and esters [1]. Many VOCs are carcinogenic or
greenhouse gases that are responsible for the depletion
of the ozone layer and photochemical smog [2]. The
control and neutralization of VOC emissions are
therefore problems of great concern. Oxidation reac-
tions are commonly used to remove organic sub-
stances. Thermal oxidation at temperatures above
900°C is typically used to neutralize VOCs. In indus-
try, however, thermal oxidation is gradually being
replaced by catalytic oxidation, which can be
employed at much lower temperatures (generally
below 500°C) [3].
Catalysts containing noble metals (e.g., Pt, Pd, Rh,
and Au) exhibit high efficiency in the oxidation of
VOCs at low temperatures [4, 5]. Their disadvantages
are high cost, deactivation caused by the sintering of
the active phase particles, and poisoning with sulfur
compounds [3]. An alternative to metal catalysts is
metal oxides, both individual and deposited on differ-
ent supports; combinations of metal oxides; and such
complex oxides as perovskites [6–8]. Supported cata-
lysts are more effective in the complete oxidation of
organic compounds, due to the dispersion of the active
component [3]. Transition and rare-earth elements
Copper oxide is a highly efficient catalyst for the
complete oxidation of CO, methane [12], ethanol,
acetaldehyde, diesel soot [13], and other organic com-
pounds [14]. Lattice oxygen O2− in CuO plays an
important role in oxidative reactions [14]. It was
shown in [15] that copper-containing catalysts exhibit
high activity in the complete oxidation of a number of
hydrocarbons, particularly toluene. Copper oxide is
typically deposited on supports with large surface
areas, e.g., CeO2, ZrO2, and zeolites. According to the
literature, the most commonly used supports for CuO
are Al2O3, CeO2, ZrO2, and Ce–Zr-based solid solu-
tions [14]. The most interesting support is zirconia
[16].
Zirconia is more effective in its so-called stabilized
form, which is obtained by doping zirconia with oxides
of metals and nonmetals (SiO2, La2O3, CaO, Y2O3,
Ce2O3) to form a solid solution with ZrO2 [15]. This
stabilization results in the crystallization of zirconia in
the tetragonal phase, the specific surface area of which
is larger than that of the more thermodynamically sta-
ble monoclinic phase. It is known that in oxidative
catalysis, the best zirconia promoters are yttrium
oxide Y2O3 and lanthanum oxide La2O3. Adding these
2140

ETHANE OXIDATION IN THE PRESENCE
2141
oxides substantially increases the number of anion ide. The sample was then dried for 24 h at 120°C and
vacancies and thus the adsorbability of oxygen. The calcined for 4 h at 750°C. The synthesized sample
content of 1–10 mol % of Y2O3/La2O3 in zirconia contained 15 wt % tungstate anions. Lanthana-stabi-
lized zirconia was prepared next. A weighed portion of
lanthanum nitrate La(NO3)3 · 6H2O was dissolved in
distilled water. Zirconium hydroxide was then sub-
jected to incipient wetness impregnation with the
solution, dried for 24 h at 120°C, and calcined for 4 h
at 400°C. The synthesized sample contained 5 wt %
La2O3.
ensures the maximum ionic conductivity [15].
Another effective way of modifying the surface of
2−
zirconia is to promote it with sulfate ions
and
SO4
2−
tungstate ions
to form so-called solid superac-
WO4
ids. The stabilization of zirconia and an increase in the
ZrO2 surface area are in this case observed. Studies of
these systems show that in with a number of metal
oxides (particularly ZrO2), such promotion increases
their catalytic activity, which exceeds that of 100% sul-
furic acid in classical acid catalysis reactions [17].
There are few published data on using solid superacids
in the complete oxidation of VOCs. The authors of [4]
studied the complete oxidation of methane in the
presence of sulfated zirconia with supported platinum,
but it was not compared to using a nonsulfated support
to confirm the appropriateness of modifying it for this
reaction.
The copper-containing catalysts were synthesized
next. Three aqueous solutions of copper nitrate were
prepared to deposit 1, 3, and 5 wt % of the metal,
respectively, on each of the synthesized supports, i.e.,
ZrO2,
5%SO4/ZrO2,
15%WO3/ZrO2,
and
5%La2O3/ZrO2. These solutions were used for the
incipient wetness impregnation of each of the sup-
ports, which were subsequently dried for 24 h at 120°C
and calcined for 4 h at 400°C. The powders of the syn-
thesized samples were compressed into pellets under a
pressure of 15 MPa and fractionated; a fraction with
particle sizes of 0.25–0.5 mm was used in our catalytic
test.
In this work, we studied the complete oxidation of
a model VOC (ethane) in the presence of catalysts
containing 1, 3, and 5 wt % CuO supported on zirco-
nia, sulfated zirconia, tungstated zirconia, and lantha-
num oxide-stabilized ZrO2.
Investigation Procedures
Thermal analysis was performed on a MOM Deri-
vatograph-C instrument. A 100-mg weighed portion
was placed in an alundum crucible. Thermogravime-
try–differential thermogravimetry–differential ther-
mal analysis (TG–DTG–DTA) curves were recorded
while linearly raising the temperature from 20 to
800°C at a rate of 10 K/min in air. The reference was
α-Al2O3. X-ray diffraction analysis was performed on
a DRON-2 diffractometer using CuKα radiation (λ =
1.514 Å). The samples were scanned in the range of
2θ = 20°–70° at a rate of 1 deg/min. The specific sur-
face area was calculated using the Brunauer–
Emmett–Teller (BET) approach, according to air
adsorption isotherms recorded at 77 K [21].
EXPERIMENTAL
Sample Synthesis Procedure
The following reactants were used to synthesize our
samples: zirconyl nitrate ZrO(NO3)2 · H2O (Acros,
99%), copper nitrate Cu(NO3)2 · 3H2O (Acros, 99%),
lanthanum nitrate La(NO3)3 · 6H2O (Acros, 99%),
ammonium paratungstate (NH4)10[H2W12O42] · 4H2O
(Acros, 99%), a 25% aqueous solution of ammonia
NH3 · H2O (Acros, reagent grade), and a concentrated
sulfuric acid H2SO4 (Khimmed, reagent grade). Zir-
conia was synthesized as described in [18]. A 0.5 M
solution of zirconyl nitrate ZrO(NO3)2 was prepared.
Under vigorous stirring, a 25% aqueous solution of
ammonia NH3 · H2O was added dropwise to the pre-
pared solution to a pH 8.4. The resulting zirconium
hydroxide gel Zr(OH)4 · xH2O was dried for 24 h at
120°C and calcined for 4 h at 400°C.
Catalytic Testing Procedure
The catalytic activity of the samples in the ethane
oxidation reaction was determined in a fixed-bed flow
reactor under atmospheric pressure. A catalyst sample
Sulfated zirconia SO4/ZrO2 was synthesized as (0.5 g) was loaded into the reactor in the form of a
fraction of 0.25–0.5 mm; a stream of the reaction mix-
ture containing 22.2 vol % of ethane and 77.8 vol % of
oxygen was fed to the catalyst at room temperature.
The O2/C2H6 molar ratio was 3.5, which corresponds
described in [19]. Zirconium hydroxide was repeatedly
subjected to incipient wetness impregnation with a
1 M solution of sulfuric acid to ensure a sulfate anion
content in the resulting sample of 5 wt %. The sample
was then dried for 24 h at 120°C and calcined for 4 h at to the stoichiometry of the complete oxidation of eth-
650°C. The WO3/ZrO2 system was synthesized as ane: C2H6 + 3.5O2 = 2CO2 + 3H2O. The feed space
velocity of the mixture was 5000 h−1. The reactor was
then heated in the temperature-programmed mode;
described in [20]. A weighed portion of ammonium
paratungstate (NH4)10[H2W12O42] · 4H2O was dis-
solved in distilled water under heating to 70°C and vig- the gas composition at the outlet of the reactor was
orous stirring. The resulting solution was used for the analyzed via chromatography while raising the tem-
incipient wetness impregnation of zirconium hydrox- perature in the catalyst bed. The gaseous conversion
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2142
DONYUSH et al.
t
t
t
t
5%Cu/ZrO2
t
t
CuO
t
ZrO2
t
t
t
5%Cu/5%SO4/
ZrO2
m
m
m
SO4/ZrO2
m
5%Cu/15%WO3/ZrO2
5%Cu/5%La2O3/ZrO2
WO3
WO3
WO3/ZrO2
La2O3/ZrO2
20
30
40
50
60
70
20
40
60
2θ, deg
2θ, deg
Fig. 1. (Color online) X-ray diffraction patterns of our
ZrO -based supports.
Fig. 2. (Color online) Diffraction patterns of the catalysts
containing 5% Cu.
2
products were analyzed on an M-3700 gas chromato-
graph equipped with a thermal conductivity detector
and a 2-m-long HayeSep-Q packed column in the iso-
thermal mode at a temperature of 60°C.
Figure 3 compares derivatograms of zirconium
hydroxide and zirconium hydroxide impregnated with
sulfuric acid. The total weight loss of freshly prepared
zirconium hydroxide upon heating from 20 to 800°C
was 22%. The weight loss occurs in several stages. At
the first stage, below 200°C, the adsorbed water is
removed [22]; ammonium nitrate then decomposes,
which apparently corresponds to the peak in the DTG
curve at 265°C and the slight exothermic effect [23].
Finally, in the temperature range of 300–400°C, coor-
RESULTS AND DISCUSSION
Physicochemical Properties
of the Supports and Catalysts
The synthesized supports and 5% copper-contain-
ing catalysts were characterized via powder X-ray dif-
fraction. Figure 1 shows the diffraction patterns of the
four synthesized supports, ZrO2, 5%SO4/ZrO2,
15%WO3/ZrO2, and 5%La2O3/ZrO2. In all cases, a
mixture of monoclinic (with diffraction peaks at 2θ =
28.17° and 31.46°) and tetragonal ZrO2 phases (with
diffraction peaks at 2θ = 30.27°, 35.25°, 50.37°,
60.20°, and 62.96°) is seen. The diffraction patterns of
sulfated zirconia and lanthanum oxide-promoted zir-
conia are almost identical to the diffraction pattern of
ZrO2. The diffraction pattern does not exhibit reflec-
tions characteristic of sulfates. The authors of [17]
showed that supported sulfate anions cannot be
detected by these means. Lanthanum oxide is presum-
ably in the X-ray amorphous state. The diffraction
pattern of the 15%WO3/ZrO2 sample exhibits reflec-
tions characteristic of the WO3 tungsten oxide phase
(with peaks at 2θ = 22° and 24.03°). Figure 2 shows
the diffraction patterns of the catalysts containing 5%
Cu. Reflections that can be attributed to copper oxide
CuO are identified (with peaks at 2θ = 38.47° and
42.20°) for all the samples.
265
411
680
DTG
DТА
Zr(OH)4
DTG
DТА
H2SO4/Zr(OH)4
exo
800
0
200
400
T, °C
600
Fig. 3. (Color online) Derivatograms of Zr(OH) and
H SO /Zr(OH) .
4
2
4
4
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ETHANE OXIDATION IN THE PRESENCE
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265
411
242
DTG
DТА
DTG
(NH4)10[H2W12O42]/Zr(OH)4
DТА
5%Cu(NO3)2/ZrO2
255
DTG
DТА
442
273
DTG
5%Cu(NO3)2/5%La2O3/ZrO2
La(NO3)3/Zr(OH)4
exo
DТА
0
exo
800
200
400
T, °C
600
800
0
200
400
T, °C
600
Fig.
(NH ) [H W
4.
(Color
online)
Derivatograms
of
Fig. 5. (Color online) Derivatograms of Cu(NO ) /ZrO
3 2
2
O
]/Zr(OH) and La(NO ) /Zr(OH) .
4 10
2
12 42
4 3 3 4
and Cu(NO ) /5%La O /ZrO .
3 2
2
3
2
dinated water is split off [22] and zirconia ZrO2 is crys- water from Cu(NO3)2 · 3H2O and the subsequent
tallized, which corresponds to the pronounced exo- decomposition of copper nitrate. These processes are
thermic effect at 410°C [18]. The total weight loss of accompanied by an endothermic effect.
freshly prepared zirconium hydroxide impregnated
with sulfuric acid upon heating from 20 to 800°C was
26.5%. The DTG curve recorded for zirconium
hydroxide impregnated with sulfuric acid is generally
similar to the above DTG curve of zirconium hydrox-
ide. The difference is that at 680°C, the DTG-curve
exhibits a peak without a pronounced heat effect that
presumably corresponds to the removal of deposited
sulfur in the form of SO3 [24].
The specific surface areas of the original zirconium
hydroxide, the four synthesized supports, and the 5%
copper-containing catalysts were determined via low-
temperature nitrogen adsorption; the results are
shown in Table 1. It is evident from the table that
unmodified zirconia had the largest specific surface
area. The results correlate with the temperatures of
calcination during the synthesis of the samples. With
5%SO4/ZrO2 and 15%WO3/ZrO2, the temperatures of
calcination were 650 and 750°C, respectively. These
results suggest the deposition of copper leads to a slight
reduction in the specific surface area of the support.
Figure 4 shows derivatograms of zirconium
hydroxide impregnated with ammonium paratung-
state and lanthanum nitrate. In the first case, the total
weight loss was 21.2%. The behavior of the DTG-
curve of zirconium hydroxide impregnated with
ammonium paratungstate is generally similar to the
behavior of the curve for zirconium hydroxide. The
difference is that, in a temperature range of 240–
320°C, (NH4)10[H2W12O42] undergoes decomposition
to form ammonia and WO3 [25]. In the second case,
the total weight loss was 34.5%. The DTG curve of zir-
conium hydroxide impregnated with lanthanum
nitrate clearly shows a peak at 273°C, accompanied by
an exothermic effect. In other respects, the behavior of
the curve is similar to that of zirconium hydroxide.
Figure 5 shows derivatograms of zirconia and lan-
thanated zirconia impregnated with copper nitrate.
The total weight loss is 5.2 and 5.5%, respectively. The
DTG curves exhibit peaks with temperatures at the
maximum of 242 and 255°C, which we attribute to the
removal of weakly bound water and crystalline hydrate
Table 1. Specific surface area (SBET, m2/g) of the supports
and the catalysts based on them
SBET
Sample
Zr(OH)4
56.6
37.0
29.2
27.1
19.6
15.7
9.9
ZrO2
5%Cu/ZrO2
5%SO4/ZrO2
5%Cu/5%SO4/ZrO2
15%WO3/ZrO2
5%Cu/15%WO3/ZrO2
5%La2O3/ZrO2
5%Cu/5%La2O3/ZrO2
24.6
17.3
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2144
DONYUSH et al.
100
80
60
40
20
0
100
80
60
40
20
0
4
3
2
4
3
2
1
1
200
300
400
500
600
200
300
400
500
600
T, °C
T, °C
Fig. 7. (Color online) Temperature dependences of ethane
conversion (α) in the presence of samples
Fig. 6. (Color online) Temperature dependences of ethane
(1) 5%SO /ZrO ,
(2) 1%Cu/5%SO /ZrO ,
4 2
conversion (α) in the presence of samples (1) ZrO ,
4
2
2
(3) 3%Cu/5%SO /ZrO , and (4) 5%Cu/5%SO /ZrO .
(2) 1%Cu/ZrO , (3) 3%Cu/ZrO , and (4) 5%Cu/ZrO .
4
2
4
2
2
2
2
100
80
60
40
20
0
100
80
60
40
20
0
4
3
2
4
3
2
1
1
200
300
400
500
600
200
300
400
500
600
T, °C
T, °C
Fig. 9. (Color online) Temperature dependences of ethane
conversion (α) in the presence of the samples:
Fig. 8. (Color online) Temperature dependences of ethane
conversion (α) in the presence of the samples:
(1) 5%La O /ZrO ,
(2) 1%Cu/5%La O /ZrO ,
2 3 2
(1) 15%WO /ZrO ,
(2) 1%Cu/15%WO /ZrO ,
3 2
2
3
2
3
2
(3) 3%Cu/5%La O /ZrO , and (4) 5%Cu/5%La O /ZrO .
(3) 3%Cu/15%WO /ZrO , and (4) 5%Cu/15%WO /ZrO .
2
3
2
2
3
2
3
2
3
2
100% ethane conversion was achieved in all cases. The
temperature of the reaction’s ignition in the presence
of pure zirconia was 375°C. The deposition of copper
lowered the temperature of the reaction’s ignition and
those of 50 and 100% conversion.
Figure 7 shows the temperature dependences of
ethane conversion for samples 5%SO4/ZrO2,
This can be attributed to CuO occupying pores in the
structure of the substrate and the particles sintering
during recalcination.
Catalytic Oxidation of Ethane
Figure 6 shows the temperature dependences of
ethane conversion for samples ZrO2, 1%Cu/ZrO2, 1%Cu/5%SO4/ZrO2, 3%Cu/5%SO4/ZrO2, and
3%Cu/ZrO2, and 5%Cu/ZrO2. The results show that 5%Cu/5%SO4/ZrO2. The results show that for the
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ETHANE OXIDATION IN THE PRESENCE
copper-containing catalysts, 100% ethane conversion REFERENCES
2145
was achieved in all cases under our test conditions.
However, the catalytic activity was considerably lower
for the support (sulfated zirconia): ethane conversion
was as low as 85% under our temperature conditions
(Tmax = 650°C). The deactivation of sulfated zirconia
that was described in [17] was thus observed. The
deposition of copper substantially lowered the tem-
perature of the reaction’s ignition and those of 50 and
100% conversion.
1. F. J. Janssen and R. A. Santen, Environmental Catalysis
(Imperial College Press, London, 1999).
2. L. Matejova, P. Topka, K. Jiratova, and O. Solcova,
Appl. Catal. A: Gen. 443, 40 (2012).
3. M. S. Kamal, S. A. Razzak, and M. M. Hossain, At-
mos. Environ. 140, 117 (2016).
4. L. M. Kustov, K. M. Skupov, S. S. Goryashchenko,
and O. V. Masloboishchikova, Zh. Fiz. Khim. 88, 891
(2014).
5. A. V. Kucherov, O. P. Tkachenko, O. A. Kirichenko,
Figure 8 shows the conversion curves for sam-
et al., Top. Catal. 52, 351 (2009).
ples
15%WO3/ZrO2,
1%Cu/15%WO3/ZrO2,
6. E. V. Makshina, L. V. Borovskikh, A. L. Kustov,
G. N. Mazo, and B. V. Romanovskii, Russ. J. Phys.
Chem. A 79, 191 (2005).
3%Cu/15%WO3/ZrO2, and 5%Cu/15%WO3/ZrO2.
It is evident that 100% ethane conversion was achieved
for all copper-containing catalysts under our test con-
ditions. As in the case above, the support (tungstated
zirconia) exhibited an extremely low catalytic activity.
At T = 650°C, ethane conversion was as low as 50%.
The deactivation of tungstated zirconia corresponds to
the data of [17]. Although this support was less active
than sulfated zirconia, this set of copper catalysts
exhibited slightly higher activity.
7. A. L. Kustov, O. P. Tkachenko, L. M. Kustov, and
B. V. Romanovsky, Environ. Int. 37, 1053 (2011).
8. N. A. Davshan, A. L. Kustov, O. P. Tkachenko, et al.,
ChemCatChem 6, 1990 (2014).
9. T. P. Otroshchenko, A. O. Turakulova, V. A. Voblikova,
L. V. Sabitova, S. V. Kutsev, and V. V. Lunin, Russ.
J. Phys. Chem. A 87, 1804 (2013).
10. Yu. P. Semushina, S. I. Pechenyuk, L. F. Kuz’mich,
and A. I. Knyazeva, Russ. J. Phys. Chem. A 91, 26
(2017).
11. I. Yu. Kaplin, E. S. Lokteva, E. V. Golubina, K. I. Masla-
kov, S. A. Chernyak, A. V. Levanov, N. E. Strokova, and
V. V. Lunin, Russ. J. Phys. Chem. A 90, 2157 (2016).
12. K. I. Slovetskaya, A. A. Greish, M. P. Vorob’eva, and
L. M. Kustov, Russ. Chem. Bull. Int. Ed. 50, 1589
(2001).
Figure 9 shows conversion curves for the set of lan-
thanum-containing
samples:
5%La2O3/ZrO2,
1%Cu/5%La2O3/ZrO2, 3%Cu/5%La2O3/ZrO2, and
5%Cu/5%La2O3/ZrO2. The results show that 100%
ethane conversion was achieved in all cases under our
test conditions. Lanthanated zirconia as a support is
better than the two previous supports, but it is inferior
to unmodified zirconia. The catalytic activity of this
set of copper-containing catalysts is also higher than
the activity of the two sets above, but it is inferior to the
activity of the first set. With respect to catalytic activ-
13. A. N. Pushkin, O. K. Gulish, D. A. Koshcheeva, and
M. S. Shebanov, Russ. J. Phys. Chem. A 87, 23 (2013).
14. Y. Fang and Y. Guo, Chin. J. Catal. 39, 566 (2018).
15. A. Bialas, T. Kondratovicz, M. Drozdec, and P. Kus-
ity, the samples are in the order 5%Cu/ZrO2
5%Cu/5%La2O3/ZrO2 > 5%Cu/15%WO3/ZrO2
>
>
trowski, Catal. Today 257, 144 (2015).
16. G. Aguila, F. Gracia, J. Cortes, and P. Araya, Appl.
5%Cu/5%SO4/ZrO2. The temperatures of 100% eth-
ane conversion are 305, 385, 410, and 419°C, respec-
tively.
Catal. B: Environ. 77, 325 (2008).
17. A. V. Ivanov and L. M. Kustov, Ross. Khim. Zh. 2, 21
(2000).
18. K. Arata, Adv. Catal. 37, 165 (1990).
19. A. V. Ivanov, E. G. Khelkovskaya-Sergeeva, and
CONCLUSIONS
T. V. Vasina, Russ. Chem. Bull. 48, 1266 (1999).
20. M. Scheifauer, R. Grasselli, and H. Knozinger, Lang-
It was found that the highest activity in the ethane
oxidation reaction is exhibited by catalysts based on
unmodified zirconia. This can be attributed to the
larger specific surface area of these samples. It was
shown via BET, XRD, and TG–DTA that the sulfa-
tion and tungstation of zirconia stabilize the tetragonal
phase of zirconia, as does adding lanthanum to it. The
decomposition of the initial compounds and the crys-
tallization of zirconia are observed below 410°C. In
addition, we may assumed that copper oxide deposited
on modified supports reacts with additives to form sul-
fate, tungstate, or cuprate, which are less active than
copper oxide.
muir 14, 30 (1998).
21. A. L. Klyachko-Gurvich, Izv. Akad. Nauk SSSR, Otd.
Khim. Nauk, No. 10, 1884 (1961).
22. A. Clearfield, G. P. D. Serrette, and A. H. Khazi-Syed,
Catal. Today 20, 295 (1994).
23. O. Kirichenko, G. Kapustin, V. Nissenbaum, et al.,
J. Therm. Anal. Calorim. 134, 233 (2018).
24. B. Reddy and M. Patil, Chem. Rev. 109, 2185 (2009).
25. L. P. Kolmakova, O. N. Kovtun, and N. N. Dovzhen-
ko, J. Siber. Fed. Univ., Eng. Technol. 3, 293 (2010).
Translated by M. Timoshinina
RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A Vol. 93 No. 11 2019