Особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля
Adsorption of zinc acetate from aqueous solution on activated carbons (AGN-2, AGN-3 and ARD) treated with nitric acid was studied in relation to the hydrodynamic conditions and temperature. The adsorption conditions for preparing active catalysts for vinyl acetate synthesis were determined.
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| Дата: | 2009 |
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Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine
2009
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Surface| _version_ | 1869291455784157184 |
|---|---|
| author | Bong, Hoang Kim Binh, Hoang Huu Kartel, N. T. Temkin, O. N. |
| author_facet | Bong, Hoang Kim Binh, Hoang Huu Kartel, N. T. Temkin, O. N. |
| author_institution_txt_mv | [
{
"author": "Hoang Kim Bong",
"institution": "Московська державна академія тонкої хімічної технології ім. М.В. Ломоносова"
},
{
"author": "Hoang Huu Binh",
"institution": "Московська державна академія тонкої хімічної технології ім. М.В. Ломоносова"
},
{
"author": "N. T. Kartel",
"institution": "Інститут хімії поверхні ім. О.О. Чуйка Національної академії наук України"
},
{
"author": "O. N. Temkin",
"institution": "Московська державна академія тонкої хімічної технології ім. М.В. Ломоносова"
}
] |
| author_sort | Bong, Hoang Kim |
| baseUrl_str | |
| collection | OJS |
| datestamp_date | 2018-11-27T09:40:12Z |
| description | Adsorption of zinc acetate from aqueous solution on activated carbons (AGN-2, AGN-3 and ARD) treated with nitric acid was studied in relation to the hydrodynamic conditions and temperature. The adsorption conditions for preparing active catalysts for vinyl acetate synthesis were determined. |
| first_indexed | 2025-07-22T19:32:14Z |
| format | Article |
| fulltext |
УДК 541.186
PECULIARITY OF FORMATION OF ZINC CATALYSTS FOR
VINYL ACETATE SYNTHESIS ON THE BASE OF MODIFIED
ACTIVATED CARBON SUPPORTS
Hoang Kim Bong, Hoang Huu Binh, N.T. Kartel*, O.N. Temkin
M.V. Lomonosov Moscow State Academy of Fine Chemical Technology
Pr. Vernadskogo 86, 117571 Moscow, Russia, E-mail: hoang46@mail.ru
*O.O. Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine
General Naumov Str. 17, 03164 Kiev, Ukraine, E-mail: nikar@kartel.kiev.ua
Adsorption of zinc acetate from aqueous solution on activated carbons (AGN-2, AGN-3
and ARD) treated with nitric acid was studied in relation to the hydrodynamic conditions and
temperature. The adsorption conditions for preparing active catalysts for vinyl acetate
synthesis were determined.
Introduction
The activity and stability of supported catalysts depends on conditions of stirring during
application of salts [1]. For example, the catalysts prepared by stirring of the support in
solution is more active and stable in vinyl acetate synthesis than catalysts prepared by simple
immersion of support in solution [2]. The ultrasonic treatment of the solution-supported system
during application of salt further increases the activity of the resulting catalysts in vinyl acetate
synthesis. Thus, the adsorption (generally sorption) is the key step in preparing active and
stable catalysts for vinyl acetate synthesis.
Along with stirring conditions and sorption temperature, important affecting the salt
distribution are the texture of support and chemical composition of the support surface. It is
known that in activated carbons the volume of micropores virtually not involved in catalysis is
46 – 50 % of the total pore volume [3]. We found that industrial activated carbons (AGN-2,
AGN-3 and ARD) this value is high as 50 %. In applying salt components, some micropores
are plugged with salt during drying of the catalyst and, as result, are not involved in catalysis.
Only mesopores playing a leading role in catalysis are accessible for adsorption of salts and
larger colloid particles from solutions. In this connection, modification of the porous structure
of carbon is the great importance. Oxidizing agents are known to change the texture and
chemical composition of the carbon surface [4]. Nitric acid may even completely decompose
the carbon structure, oxidize humic acid, and yield aromatic policarboxilic acid. Controlled
oxidation of carbon with nitric acid increases the number of surface proton-donor groups and
may change the carbon porosity. Furthermore, natural impurities or industrial additives (metal
oxides) sorbed on the surface of carbon crystallites are dissolved in nitric acid.
Taking into account the above consideration, we studied in this work the sorption of
zinc acetate during forced circulation of its solution through a bed of AGN-2, carbons treated
with nitric acid. The solution was fed in reaction vessel in to ways: from the top down
(hereinafter referred to as fixed bed) and from bottom upwards (hereinafter referred to as
fluidized bed). The impregnation is the key step in preparation of sorption catalysts.
Experimental
Carbon treated with nitric acid was placed in a 350 ml cylindrical glass vessel 45 mm in
diameter, equipped with a jacket. To prevent loss of carbon from the reaction zone, the carbon
bed was fixed at both ends with filters.
The sorption was studied at temperatures from 0 to 85 °C under static conditions or
with circulation of an aqueous solution of Zn(CH3COO)2 with various flow velocities through
mailto:hoang46@mail.ru
mailto:nikar@kartel.kiev.ua
fixed and fluidized carbon beds for 7 – 8 h until a constant Zn(CH3COO)2 concentration in
solution was attained. In all experiments the solution to activated carbon volume ratio was
10:1. The total content of the salt in carbon was determined from the difference between the
salt concentration in solution prior to attainment of the sorption equilibrium and the
equilibrium concentration. The Zn(CH3COO)2 concentration was determined by titration with
0.05 M solution of Na2EDTA and by interferometer. The accuracy of determination of the salt
content in the carbon phase was ±0.013 mmol g-1. The relative difference between the
concentrations determined by both methods did not exceed 6.5 %. After impregnation, carbon
was filtered off and dried at 175 – 180 °C in hot nitrogen flow. The surface area, porosity, and
activity of the resulting catalyst were measured.
The activity of catalysts was measured at 175, 205, and 230 °C in flow-through unit at
4.2 g l-1 h-1 constant space velocity of a C2H2:CH3COOH:N2 (4:4:1) mixture. The unit was
described in detail in [4].
Results and discussion
By the example of AGN-2 we demonstrate that the specific surface area and porosity of
carbon considerably change after treatment. The volumes of meso- and macropores increase by
a factor 1.5, and the micropores volume decreases by 14 %. Thus, the chemical treatment
resulting in oxidation of humic acids and polycondensed structures and dissolution of oxide
impurities on the carbon surface changes the pore distribution and decreases the specific
surface area to 160-180 cm2×g-1, owing to enlargement of micropores. The total concentration
of acid groups is 1.2 in g-equivalent NaOH [3].
Comparison of kinetic curves of Zn(CH3COO)2 sorption on initial carbons and carbons
treated with nitric acid at 50 °C from solutions with 15 and 19 wt % of the salt shows
(Fig. 1, a) that sorption rate of the treated carbons increases about 2.8 times within the first
1.5 h. The total amount of sorption increases about 1.75 times (19 % solution, 4 h). After
performing, sorption the surface area of the treated and initial samples decreases from 690 to
80 – 90 and from 870 to 194 m2×g-1 respectively.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 50 100 150 200 250
t
1
1'
2
2'
a, mmol.g-1
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 50 100 150 200
a, mmol.g-1
t
4'
3'
4
3
a b
Fig. 1. Kinetic curves of Zn(CH3COO)2 sorption from aqueous on AGN-2 carbon. (a)
Sorption (mmol×g-1) and (t) time (min); (a) AGN-2: (1, 2) treated with nitric acid
and (1’, 2’) initial. (b) carbon bed: (3, 4) fluidized and (3’, 4’) fixed. Solution
temperature 50 °C. Concentration of solution ceq (wt %): (1,1’) 19, (2, 2’) 15, (3, 3’)
12 and (4, 4’) 25.
The stirring condition also have a strong effect on the sorption rate (Fig. 1b) and, as
further studies showed, on activity and stability of the catalysts in vinyl acetate synthesis. It
should be noted that even at continuous circulation of a solution with 12.1 cm s-1 flow velocity
through the carbon bed the sorption rate in fluidized bed increases 5-6 times within first 30 min
as compared with fixed bed. In all subsequent experiments the zinc acetate sorption was
studied in fluidized bed.
Varying the circulation flow velocity of zinc acetate solution in the range from 7 to 20
cm×s-1 showed the optimal flow velocity is 12-15 cm×s-1. Increasing the circulation flow
velocity reduces the catalytic activity (Table 1).
Table 1. Activity of catalysts prepared at various flow velocities of circulating Zn(CH3COO)2
solution (c0 » 19 wt %, T=50 °C)
Sample* V, cm×sec-1 Catalytic activity
at 230 oC, g×l-1×h-1
K8
K10
K12
K14
K16
K18
6.8
9.0
12.2
15.0
17.4
20.3
82.0
95.9
105.9
107.7
97.4
85.8
* The content of the zinc acetate in all catalysts was 24-25 wt%
The circulation rate of the solution in the interval V = 7-60 cm.sec-1 [2] has a very
noticeable influence upon catalyst. The maximum activity was reached at V = 15¼18 cm.sec-1
(195 g×l-1×h-1 at 230 °C) (Fig. 2).
Extremes are observed on the curve Ssp-V too. The circulation velocity influences the
distribution of pores volume on radii and the value of pore volumes.
The sorption of zinc acetate differs from that of HgCl2 [5] in a higher pH of the solution
and the appearance of maxima in the a–t curves. As is seen from Fig. 3, the maximal amount
of sorption is the higher and attained the faster, the higher the pH of the initial solution. In the
case the equilibrium amount of sorption remains virtually constant, irrespective of the pH of
the initial solution, and the pH of the equilibrium solutions is 4.9±0.1. In all cases the pH of the
solution increases during the sorption and at the maximal amount of sorption slightly exceeds
the pH of the equilibrium solution. At large volume excess of the circulating solution with
respect to the catalyst (10:1) the maximal amount of sorption amax is almost independent of the
equilibrium salt concentration on the solution ceq over entire range of the tested initial
concentration of Zn(CH3COO)2. It should also be noted that sorption under static conditions
(without stirring) is described by ordinary Langmuir isotherms without maxima [3].
Variation of the initial concentration of zinc acetate showed that at 50 °C the
dependence of the catalytic activity of the treated catalysts on c0 (at one and the same content
of the salt in the catalyst) passes through maximum at the initial concentration 19 – 20 wt %.
Further increase of the initial concentration reduces the catalytic activity by 30 – 40%.
Dependence of Ssp and amount of adsorbed salt (a) upon initial concentration in the internal 3-
33 (wt %) looks unusual as well (Fig. 4).
When temperature of deposition is changed in the interval of 0 – 80 °C (Tmax= 50 °C)
initial adsorption rates and the amount of supported salt (in 1, 2, 3 hours) become sharply
dependent upon it (Fig. 5). Catalyst activity in vinyl acetate synthesis passes through maximum
values at 50 °C too. There is observed an extreme change of Ssp at 20-80 °C (49 m2 at 20 °C,
90 m2 at 50 °C and 37 m2 at 80 °C) as well.
v, cm s-1
0
50
100
150
200
250
0 40 60 8020
Ssp , m2×g-1; A, gVA×l-1×h-1, C, (wt)%
1
2
3
а, mmol×g-1
t, h
Fig. 2. Dependence of the catalysts
characteristics from circulation flow
velocity. (1)-Surface (S), (2)-
Catalytic activity (A), (3) -amount of
Zn(OAc)2 in catalyst, (C).
Fig. 3. Sorption of Zn(CH3COO)2 from its
19 % aqueous solution on activated
carbon at T=50 °C as a function of pH
of the initial solution. (a) Sorption
(mmol×g-1) and (t) time (h). pH: (1)
5.05, (2) 4.00 and (3) 2.95.
0
20
40
60
80
100
0 3 9 15 21 27 33
1.1
1.2
1.3
1.4
Ssp а, (mmоl×g-1), m2×g-1
Starting concentration (wt, %)
а, mmol×g-1
T
Fig. 4. Dependence of the catalyst
characteristics Zn(OAc)2/C on
starting salt concentration in aqueous
solution.
Fig. 5. Dependence of amount of zinc
acetate adsorbed on activated carbon
treated with nitric acid vs.
temperature T (0C). Adsorption
duration (min): (1) 60, (2) 120 and
(3) 180.
In accordance with these dependences it is evident that the process of Zn(OAc)2
deposition is a complex process involving Zn(OAc)2 adsorption and ion exchange of different
forms of Zinc salts (exothermic and endothermic steps, changing of pH during adsorption) on
oxidized AC surface.
The well pronounced extremes found for the temperatures dependences of the sorption
rate and the amount of sorption of zinc acetate were also found for the dependence of catalytic
activity on the temperature of application of zinc acetate (Table 2). The catalysts prepared at
50°C are highly active.
The acceleration of the sorption with increasing pH of initial solution after addition of
KOH is likely to be due to partial neutralization of acidic functional groups to form K+-
substituted groups, which actively exchange K+ with zinc acetate by the reaction
O-K+ + Zn(CH3COO)2 O-Zn+(CH3COO) + K+(CH3COO)-
Table 2. Catalytic activity of zinc acetate catalysts prepared at various temperatures
(V = 15 cm×s-1, c0 19.5 wt%)
Sample T, °C Catalytic activity at 230 °C,
g×l-1×h-1
K8
K10a
K12a
K14
K16a
K18a
20
30
40
50
55
65
68.3
79.5
99.7
107.2
89.8
74.2
The second reaction is the more active sorption of partially hydrolyzed mono- and
polynuclear compounds containing –Zn-OH group. The increase in pH during sorption can be
explained by binding to the carbon surface of acetic acid formed in reaction of Zn(CH3COO)2
with strongly acidic carboxyl groups or with water (hydrolysis).
The appearance of maxima on the kinetic curves obtained in the case of intense
hydrodynamic application of the salt can be explained by the fact that the sorption rate under
these conditions is higher than the rate of attainment of particular equilibria on the surface (ion
exchange, oligomerization and hydrolysis of zinc acetate, and sorption of acetic acid). As a
result in the first steps the sorbent becomes supersaturated with zinc acetate and only them the
sorption equilibrium is attained. Under static conditions (without stirring) the sorption of zinc
acetate monotonically increases up to the equilibrium value.
Thus, the sorption of zinc acetate from aqueous solution on the carbon surface (which
we term as adsorption) involves adsorption of zinc acetate in various forms (including the
hydrolysis products) and probably ion-exchange process.
Probably, in concentrated solutions of zinc acetate, different forms of zinc acetate are
adsorbed on oxidized activated carbons by different mechanisms.
We suggest that the sorption equilibrium is attained via the following endothermic and
exothermic stages: (1) dehydration of hydrated zinc acetate molecules (DH>0); (2) dehydration
of the surface, i.e., rupture of hydrogen bonds between water molecules and the surface
(especially surface functional groups, DH>0); (3) sorption of zinc acetate molecules (DH<0);
(4) dimerization and oligomerization of zinc acetate on the surface to form bridging acetate
groups (DH<0); and (5) ion exchange of zinc acetate with oç¾OH and oç¾O-K+ groups
(may be both exothermic and endothermic).
If several zinc acetate species are immobilized on the surface by sorption ion exchange
mechanisms (including oligomerization), this is sufficient for a combination of exothermic and
endothermic processes to result in extremal dependences.
Conclusions:
Thus the most active catalysts can be prepared under the following conditions:
concentration of the initial solution 19-20 wt%; flow velocity of circulating solution 12-15
cm×s-1; tenfold volume excess of the solution temperature 50 °C.
The condition of oxidation of activated carbon and hydrodynamic parameters of
circulation will be refiner publications.
References
1. Neimark A.V., Kheifer L.J., Fenelonov V.B. НАЗВА // Ind. and Eng. Chem. Prod.
Res. and Develop. – 1981. – V. 20, № 5. – P. 439 – 450.
2. Romenskii, A.V., Lobeiko, A. Ya., Abroshchenko V.I. НАЗВА // Khim. Tekhnol. –
1986. – № 6. – P. 39 – 42.
3. НАЗВА / Hoang Kim Bong, A.N. Nyrkova, M.M. Chobanu, G.K. Shestakov,
O.N. Temkin // Russ. J. Appl. Chem. – 1997. – V. 70, № 12. – P. 1872 – 1878.
4. НАЗВА / Hoang Kim Bong, Abanto Chavez, A.N. Nyrkova, G.K. Shestakov,
O.N. Temkin // Russ. J. Appl. Chem. – 1998. – V. 71, № 1. – P. 96 – 102.
5. Khoang Kim Bomg, Temkin O.N. НАЗВА // Catalysts of biotechnology, of chemical
and chemical technology // Proc. of All-Russian Conf. – Moscow, May 1999. – P. 99 –
101.
ОСОБЕННОСТИ ФОРМИРОВАНИЯ ЦИНКОВЫХ
КАТАЛИЗАТОРОВ СИНТЕЗА ВИНИЛАЦЕТАТА НА
ОСНОВЕ НОСИТЕЛЕЙ ИЗ МОДИФИЦИРОВАННОГО
АКТИВНОГО УГЛЯ
Хоанг Ким Бонг, Хоанг Хю Бинх, Н.Т.Картель* и О.Н.Тёмкин
Московская государственная академия тонкой химической
технологии им. М.В. Ломоносова
пр. Вернадского 86, 117571 Москва, Россия, E-mail: hoang46@mail.ru
*Институт химии поверхности им. А.А. Чуйко Национальной академии наук Украины
ул. Генерала Наумова 17, 03164 Киев, E-mail: nikar@kartel.kiev.ua
Изучена адсорбция ацетата цинка из водных растворов на активированных углях
(АГН-2, АГН-3 и АРД), обработанных азотной кислотой, при разных гидродинамичес-
ких условиях и температурах. Определены адсорбционные условия для приготовления
активных катализаторов синтеза винилацетата.
ОСОБЛИВОСТІ ФОРМУВАННЯ ЦИНКОВИХ
КАТАЛІЗАТОРІВ СИНТЕЗУ ВІНІЛАЦЕТАТУ НА ОСНОВІ
НОСІЇВ З МОДИФІКОВАНОГО АКТИВНОГО ВУГІЛЛЯ
Хоанг Кім Бонг, Хоанг Хю Бінх, М.Т.Картель* и О.М.Тьомкін
Московська державна академія тонкої хімічної технології ім. М.В. Ломоносова
пр. Вернадського 86, 117571 Москва, Росія, E-mail: hoang46@mail.ru
*Інститут хімії поверхні ім. О.О. Чуйка Національної академії наук України
вул. Генерала Наумова 17, 03164 Київ, Україна, E-mail: nikar@kartel.kiev.ua
Вивчена адсорбція ацетату цинку з водних розчинів на активованих вуглях (АГН-2,
АГН-3 та АРД), оброблених азотною кислотою, при різних гідродинамічних умовах та
температурах. Визначені адсорбційні умови для приготування активних каталізаторів
синтезу вінілацетату.
mailto:hoang46@mail.ru
mailto:nikar@kartel.kiev.ua
mailto:hoang46@mail.ru
mailto:nikar@kartel.kiev.ua
Introduction
Experimental
Results and discussion
|
| id | oai:ojs.pkp.sfu.ca:article-337 |
| institution | Surface |
| keywords_txt_mv | keywords |
| language | English |
| last_indexed | 2026-03-12T17:08:58Z |
| publishDate | 2009 |
| publisher | Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine |
| record_format | ojs |
| resource_txt_mv | surfacezbircomua/e5/1cbb83ef11d4091e94e7321d35fbf9e5.pdf |
| spelling | oai:ojs.pkp.sfu.ca:article-3372018-11-27T09:40:12Z Peculiarity of formation of zinc catalysts for vinyl acetate synthesis on the base of modified activated carbon supports Особенности формирования цинковых катализаторов синтеза винилацетата на основе носителей из модифицированного активного угля Особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля Bong, Hoang Kim Binh, Hoang Huu Kartel, N. T. Temkin, O. N. Adsorption of zinc acetate from aqueous solution on activated carbons (AGN-2, AGN-3 and ARD) treated with nitric acid was studied in relation to the hydrodynamic conditions and temperature. The adsorption conditions for preparing active catalysts for vinyl acetate synthesis were determined. Изучена адсорбция ацетата цинка из водных растворов на активированных углях (АГН-2, АГН-3 и АРД), обработанных азотной кислотой, при разных гидродинамических условиях и температурах. Определены адсорбционные условия для приготовления активных катализаторов синтеза винилацетата. Вивчена адсорбція ацетату цинку з водних розчинів на активованих вуглях (АГН-2, АГН-3 та АРД), оброблених азотною кислотою, при різних гідродинамічних умовах та температурах. Визначені адсорбційні умови для приготування активних каталізаторів синтезу вінілацетату. Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2009-08-02 Article Article application/pdf https://surfacezbir.com.ua/index.php/surface/article/view/337 Surface; No. 15 (2009): Chemistry, Physics and Technology of Surface; 138-143 Поверхность; № 15 (2009): Химия, физика и технология поверхности; 138-143 Поверхня; № 15 (2009): Хімія, фізика та технологія поверхні; 138-143 3154-8091 3154-8083 en https://surfacezbir.com.ua/index.php/surface/article/view/337/334 Авторське право (c) 2009 Hoang Kim Bong, Hoang Huu Binh, N.T. Kartel, O.N. Temkin |
| spellingShingle | Bong, Hoang Kim Binh, Hoang Huu Kartel, N. T. Temkin, O. N. Особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля |
| title | Особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля |
| title_alt | Peculiarity of formation of zinc catalysts for vinyl acetate synthesis on the base of modified activated carbon supports Особенности формирования цинковых катализаторов синтеза винилацетата на основе носителей из модифицированного активного угля |
| title_full | Особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля |
| title_fullStr | Особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля |
| title_full_unstemmed | Особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля |
| title_short | Особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля |
| title_sort | особливості формування цинкових каталізаторів синтезу вінілацетату на основі носіїв з модифікованого активного вугілля |
| url | https://surfacezbir.com.ua/index.php/surface/article/view/337 |
| work_keys_str_mv | AT bonghoangkim peculiarityofformationofzinccatalystsforvinylacetatesynthesisonthebaseofmodifiedactivatedcarbonsupports AT binhhoanghuu peculiarityofformationofzinccatalystsforvinylacetatesynthesisonthebaseofmodifiedactivatedcarbonsupports AT kartelnt peculiarityofformationofzinccatalystsforvinylacetatesynthesisonthebaseofmodifiedactivatedcarbonsupports AT temkinon peculiarityofformationofzinccatalystsforvinylacetatesynthesisonthebaseofmodifiedactivatedcarbonsupports AT bonghoangkim osobennostiformirovaniâcinkovyhkatalizatorovsintezavinilacetatanaosnovenositelejizmodificirovannogoaktivnogouglâ AT binhhoanghuu osobennostiformirovaniâcinkovyhkatalizatorovsintezavinilacetatanaosnovenositelejizmodificirovannogoaktivnogouglâ AT kartelnt osobennostiformirovaniâcinkovyhkatalizatorovsintezavinilacetatanaosnovenositelejizmodificirovannogoaktivnogouglâ AT temkinon osobennostiformirovaniâcinkovyhkatalizatorovsintezavinilacetatanaosnovenositelejizmodificirovannogoaktivnogouglâ AT bonghoangkim osoblivostíformuvannâcinkovihkatalízatorívsintezuvínílacetatunaosnovínosíívzmodifíkovanogoaktivnogovugíllâ AT binhhoanghuu osoblivostíformuvannâcinkovihkatalízatorívsintezuvínílacetatunaosnovínosíívzmodifíkovanogoaktivnogovugíllâ AT kartelnt osoblivostíformuvannâcinkovihkatalízatorívsintezuvínílacetatunaosnovínosíívzmodifíkovanogoaktivnogovugíllâ AT temkinon osoblivostíformuvannâcinkovihkatalízatorívsintezuvínílacetatunaosnovínosíívzmodifíkovanogoaktivnogovugíllâ |