The Effect of the Active Component Content on the Catalytic Activity of Nickel Sulfide Catalysts in Olefin Synthesis from Stearic Acid

Article abstract of DOI:10.1134/S0965544119060112

Abstract: The effect of active component content on the catalytic activity of supported sulfide catalysts in the synthesis of C₁₇ olefins from stearic acid has been studied. It has been shown that an increase in the nickel content leads to a decrease in the catalyst activity; in addition, there is a negative correlation between the activity and the fraction of large particles on the support surface. The highest heptadecene selectivity (50–60%) is observed for alumina-supported catalysts owing to the higher degree of dispersion of the active component.

Full text of DOI:10.1134/S0965544119060112

ISSN 0965-5441, Petroleum Chemistry, 2019, Vol. 59, No. 6, pp. 622–628. © Pleiades Publishing, Ltd., 2019.
The Effect of the Active Component Content on the Catalytic Activity
of Nickel Sulfide Catalysts in Olefin Synthesis
from Stearic Acid
a,
a
a
a
E. A. Katsman *, V. Ya. Danyushevsky , V. M. Karpov , P. S. Kuznetsov ,
a
a
O. N. Shishilov , and A. S. Berenblyum
a
Institute of Fine Chemical Technologies (Moscow Technological University), Moscow, Russia
e-mail: katsman@aha.ru
Received November 24, 2018; revised December 15, 2018; accepted February 12, 2019
*
Abstract—The effect of active component content on the catalytic activity of supported sulfide catalysts in the
synthesis of C olefins from stearic acid has been studied. It has been shown that an increase in the nickel
1
7
content leads to a decrease in the catalyst activity; in addition, there is a negative correlation between the
activity and the fraction of large particles on the support surface. The highest heptadecene selectivity (50–
6
0%) is observed for alumina-supported catalysts owing to the higher degree of dispersion of the active com-
ponent.
Keywords: decarbonylation, stearic acid, nickel sulfide catalyst, silica gel, alumina, optimization
DOI: 10.1134/S0965544119060112
The use of renewable raw materials in the chemical component, and the nature of the support can also
industry has abruptly increased in the recent two to have a considerable effect [7–9].
three decades [1]. Currently, much attention is being
paid to the production of higher olefins from various
inedible fats and fatty acids derived from them [2].
However, the number of studies of the above issues
is still insufficient to provide a targeted synthesis of
catalysts required for actual practice. Note that the
establishment of correct correlations between the
physicochemical characteristics of a catalyst and the
catalyst efficiency requires a correct choice of catalyst
synthesis and testing procedures.
This study is focused on the effect of the active
component content in the catalyst on the catalyst effi-
ciency in the commercially significant stearic acid (St)
decarbonylation reaction.
In the development of supported catalysts, increas-
ing attention is being given to the role of the size,
shape, composition, and other characteristics of parti-
cles of catalytically active compounds, particularly
nanoparticles. It was shown that the catalyst activity in
the electrochemical oxidation of methanol decreases
with a decrease in the particle size below 5 nm [3]. The
presence of a size effect was also observed in the allyl
alcohol hydrogenation reaction catalyzed by Pd
nanoparticles. Thus, an increase in the Pd particle size
from 1.3 to 1.9 nm leads to a significant increase in cat-
alytic activity [4]. The effect of the Pd nanoparticle
size in a range of 9–40 nm was studied in the electro-
chemical oxidation of formic acid [5]. In this range,
the catalytic activity of Pd particles increases with a
decrease in their size. A decrease in Cu particle size
also leads to an increase in catalytic activity in the
EXPERIMENTAL
Support Preparation Procedure
2
The catalyst supports were γ-Al O (254 m /g) and
2
3
2
silica gel KSKG (205 m /g). The support was ground
to select a fraction of 80–200 μm; the fraction was
dried at 120°C for 2 h.
electrochemical reduction of CO . Moreover, in this
2
Catalyst Synthesis Procedure
A calculated weighed portion of reagent-grade
case, the direction of the reaction also changes: at a
particle size of less than 3 nm, the formation of hydro-
carbons ceases and carbon monoxide becomes the nickel sulfate heptahydrate was dissolved in 10 mL of
main product [6]. It is not only the particle size that distilled water and poured to 5 g of the respective sup-
plays a significant role; the nanoparticle shape, the port; the resulting mixture was stirred for 1 h. The
oxidation state and internal structure of the active resulting suspension in a porcelain cup was placed in a
622

THE EFFECT OF THE ACTIVE COMPONENT CONTENT
623
drying cabinet to evaporate excess water at a tempera- and 0.75 g of the support, and 0.167 g of the 9%Ni cat-
ture of 80°C under occasional stirring for 2 h; after alyst and 0.833 g of the support.
that, the temperature was increased to 140°C and the
In procedure 2, with an increase in the active com-
mixture was held at this temperature under occasional
ponent content in the catalyst, a constant amount of
stirring for 3 h.
the active component (0.015 g) and an almost constant
amount of the support in the reactor are maintained.
The total amount of the catalyst and the pure support
Catalyst Reduction in Hydrogen Stream
in the reactor is maintained at a constant level of 1 g.
The catalyst was reduced in situ in a 50-mL (liquid)
stainless steel autoclave (Autoclave Engineers, United
States) equipped with an electric furnace and a stirrer.
A weighed portion of the catalyst of 0.5 or 1 g was
placed in the autoclave, which was subsequently twice
flushed with hydrogen. After that, reduction was run
at a temperature of 350°C, a hydrogen flow rate of 2–
In this case, a change in the catalytic reaction param-
eters can be caused by a change in the properties of the
active component particles on the support surface
owing to a change in the active component concentra-
tion in the catalyst. The effect of the active component
content in the reactor is eliminated. It was found that,
in the blank test, the St conversion is negligible; how-
ever, to provide the integrity of the test, the support
content in the reactor is maintained at a constant level.
3
L/h, and a pressure of 10 atm under stirring of the
gaseous medium (300 rpm, with the stirrer placed
above the catalyst surface) for 3 h. After that, the reac-
tor was cooled to room temperature using a water bath;
excess hydrogen was removed to a pressure slightly
higher than atmospheric pressure (by 0.5–1 atm);
next, to provide the reaction, 8 mL of a solvent
Product Analysis
The gaseous reaction products were analyzed on an
LKhM-80 gas chromatograph equipped with a ther-
mal conductivity detector and columns packed with
zeolite 5A and Porapak Q using argon as a carrier gas
at a flow rate of 14 and 30 mL/min, respectively; the
column temperature was 100 and 25°C, respectively.
The evaporator and detector temperature was 100°C.
The detector current was 100 mA.
(
dodecane) were introduced into the reactor under
nitrogen pressure through a special vessel. Dodecane
was fed through a vessel to prevent the catalyst from
contacting with air during the subsequent loading
of St.
Catalytic Testing Procedure
Analysis of liquid products. The reaction mixture in
the reactor was heated to 70°C to convert it into a liq-
uid state and then stirred. An aliquot of 1–1.5 g was
taken for analysis by the titration method. A weighed
portion was dissolved in a chloroform–ethanol mix-
ture (volume ratio of 1 : 1), which was preadjusted to a
pH of 7 with a 0.1 M KOH solution. Five or six drop-
lets of an indicator (phenolphthalein) were added to
the solution; titration was conducted with a 0.1 M
NaOH solution in ethanol until a 30-s stability of the
indicator color. The titration results were used to
determine the unreacted St concentration and calcu-
late the St conversion.
The tests were conducted in accordance with two
procedures with different designs of experiment.
Procedure 1 (conventional). A catalyst in an amount
of 0.50 g was loaded into the autoclave and reduced
with hydrogen. Next, 2.00 g of reagent-grade St were
loaded into the autoclave with the reduced catalyst and
dodecane. The autoclave was twice flushed with
hydrogen to set the initial pressure of 14 atm. After
that, the reactor was heated to 350 and 325°C for cat-
alysts supported on γ-Al O and silica gel, respectively;
2
3
the reaction was run under vigorous stirring
(
1000 rpm, with the stirrer immersed into the reaction
Product analysis by gas–liquid chromatography. To
eliminate errors in gas–liquid chromatography analy-
sis, St-containing liquid products were preliminarily
methylated as follows: 7 mL of a 1 N H SO solution
mixture) for 2 h. After reaction, the reactor was rapidly
cooled to room temperature using a water bath. The
catalytic test was repeated two or three times.
2
4
In this procedure, with an increase in the active
component content in the catalyst, a constant amount
of the catalyst in the reactor is maintained, while the
active component content in the reactor increases.
The catalytic tests are conducted at the different
temperatures because the activity of the silica gel-sup-
ported catalyst is higher than the activity of the alu-
mina-supported catalyst [10, 11].
in methanol were added to an aliquot (2 g); the result-
ing mixture was refluxed for 1 h. Reaction products
were isolated by extraction with heptane. Extraction
with 3.3 mL of heptane was conducted three times;
after that, the extract was water-washed from sulfuric
acid until a neutral reaction of wash water according to
the indicator. Tridecane used as an internal standard
(1.5–2.5 wt %) was added to an aliquot of the extract
Procedure 2 (proposed). The catalytic tests were (1.3–1.5 g). Analysis was conducted on a Kristall-
conducted similarly to procedure 1, yet with the fol- 2000M gas–liquid chromatograph equipped with an
lowing catalyst loads: 1 g of the support (blank test), HP ULTRA 2 column coated with a polymethylsilox-
1
g of the 1.5%Ni catalyst, 0.5 g of the 3%Ni catalyst ane + 5% polyphenylsiloxane stationary phase; the
and 0.5 g of the support, 0.25 g of the 6%Ni catalyst flow rate of nitrogen used as a carrier gas was
PETROLEUM CHEMISTRY Vol. 59 No. 6 2019

6
24
KATSMAN et al.
%
%
1
00
100
9
0
0
Conversion
9
0
Olefin selectivity
Olefin yield
8
Conversion
80
7
0
Heptadecene selectivity
Heptadecene yield
Heptadecane selectivity
7
0
Heptadecane selectivity
6
5
4
3
2
0
0
0
0
0
6
5
4
3
2
0
0
0
0
0
1
0
1
0
0
0
1
.5
3.0
4.5
6.0
7.5
9.0
1
.5
3.0
4.5
6.0
7.5
9.0
Nickel content in the catalyst, %
Nickel content in the catalyst, %
Fig. 1. Dependence of the catalytic reaction parameters on
Fig. 2. Dependence of the catalytic reaction parameters on
metal concentration on the silica gel support (catalyst
charge of 0.5 g, varying active component content in the
reactor).
metal concentration on the γ-Al O support (catalyst
2
3
charge of 0.5 g, varying active component content in the
reactor).
1
mL/min. The following programming of the column with the earlier conclusion that nickel hydrides formed
temperature was used: 60°C for 5 min, temperature under the action of hydrogen on the active component
increase to 250°C at a rate of 10 deg/min, and holding of catalysts are capable of inhibiting the side reaction
at 250°C for 20 min. The evaporator and detector tem- of olefin oligomerization [11].
perature was 270 and 250°C, respectively. Analysis
For the two supports, despite the increasing
results were processed as described in [10, 11]. The St
amount of the active component in the reaction mix-
concentrations determined by titration and chroma-
ture, the increase in the conversion is not monoto-
tography coincide within ±5 rel %.
nous: initially, upon switching from the 1.5%Ni cata-
lyst to the samples containing 3–6 wt % Ni, the con-
version quite rapidly increases; afterwards, the
increase ceases. Similar dependences were observed
previously for other catalysts [10, 12, 13].
Studies of Catalysts Supported on γ-Al O and Silica Gel
2
3
To study the efficiency of catalysts as a function of
Ni content in them, a set of catalysts containing 1.5,
.0, 6.0, and 9.0 wt % Ni was prepared. The catalysts
3
Note that, although the relationships found for the
were reduced and subjected to catalytic tests in accor- alumina- and silica gel-supported catalysts are similar,
dance with procedures 1 and 2. The resulting reaction the olefin yield in the presence of the latter is signifi-
mixture was weighed and analyzed as described above. cantly higher.
The results were used to obtain the material balance
The dependence of catalyst efficiency on the active
with an imbalance not exceeding 5% and calculate the
component concentration in the sample was refined
St conversion and the heptadecene and heptadecane
using catalytic tests in accordance with procedure 2.
selectivities.
Analysis of the data shows that, for the two sup-
In addition, the catalysts were studied by transmis-
ports, the St conversion also passes through a maxi-
sion electron microscopy (TEM) on a LEO 912 AB
mum, yet at a Ni concentration in the catalyst of ~3%
OMEGA microscope at an accelerating voltage of
(
Figs. 3, 4). With an increase in the nickel concentra-
1
00 kV.
tion in the catalyst, olefin selectivity increases for alu-
mina and passes through a maximum for silica gel. In
this case, the selective conversion via the side reaction
of olefin hydrogenation to form heptadecane
decreases for both supports. As discussed earlier, in
this case, the reaction parameters can be changed if
the catalytic properties of the active component
depend on the concentration of it in the catalyst, in
other words, on the properties of the active particles on
the support surface.
RESULTS AND DISCUSSION
In general, St deoxygenation includes the following
stages: St decarbonylation to heptadecenes (target
reaction) and the hydrogenation and oligomerization
of heptadecenes (secondary reactions) [11].
Let us discuss the dependence of the catalytic reac-
tion parameters obtained in accordance with proce-
dure 1 on the metal content in the catalyst (Figs. 1, 2).
It is evident that, in the presence of the alumina- and
To reveal possible causes of the observed depen-
silica gel-supported catalysts, the olefin selectivity dences, the catalysts with a nickel content of 6 and 9%
exhibits a tendency to increasing with an increase in were studied by TEM (Figs. 5a–5d) combined with X-
the nickel content in the catalyst. This feature is in ray microdiffraction (Tables 1–4). The results were
agreement with the consecutive reaction pattern and analyzed using the following XRD JCPDS database
PETROLEUM CHEMISTRY
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THE EFFECT OF THE ACTIVE COMPONENT CONTENT
625
%
that in the catalysts containing 6% Ni (fraction of
larger particles increases). Thus, the dependence of
the catalyst efficiency parameters on the active com-
ponent content in the catalysts can be attributed to a
change in the fraction of large particles, i.e., the effect
of the degree of dispersion (so-called “size effect”).
This effect is generally associated with a decrease in
the contribution of surface atoms in the active catalyst
particles with an increase in their size and a change in
their coordination capabilities, which are caused by
various factors, such as a respective change in the sur-
face curvature [15].
Analysis of the diffraction patterns shows the fol-
lowing. In general, the patterns for alumina and silica
gel are similar. For the 6.0%Ni catalysts, the number
of identified interplanar distances (IPDs) is larger
than that in the 9.0%Ni samples (Tables 1–4).
100
Conversion
Heptadecene selectivity
Heptadecene yield
Heptadecane selectivity
9
8
0
0
70
6
5
4
3
2
0
0
0
0
0
10
0
1
.5
3.0
4.5
6.0
7.5
9.0
Nickel content in the catalyst, %
Fig. 3. Dependence of the catalytic reaction parameters on
metal concentration on the γ-Al O support (catalyst
2
3
charge of 1 g, constant active component content in the
reactor).
Most of the identified IPDs are fairly close to the
IPDs for crystalline sulfides Ni S and NiS. The num-
3
2
ber of these IPDs in the 9.0%Ni catalyst changes in
favor of NiS compared with the 6%Ni sample. In
addition, there are IPDs that can be ascribed to nickel
oxide NiO. It is not improbable that nickel is partially
incorporated into the crystal lattice of oxide supports
cards: Ni, 45-1027, 04-0850; NiO, 04-0835; NiS, 47-
1739; and Ni S , 44-1418 [14].
3 2
Figures 5a and 5c show that, at an active compo-
[16]. Some of the IPDs can be attributed to character-
nent concentration of 6.0% in terms of nickel, in the
presence of the two supports, the size distribution his-
togram is unimodal and almost symmetrical. The par-
ticle shape is nearly spherical. In the case of the alu-
mina and silica gel supports, the average particle size is
istic values of metallic nickel. However, it is impossi-
ble to unambiguously determine whether reduced
nickel is present or absent, because both the amor-
phous state of the material and small sizes of metal
particles or their low concentration can hinder the
reliable identification of IPDs.
3
.1 ± 1.0 and 5.2 ± 1.2 nm, respectively, and the parti-
cle size varies in a range of 1–6 and 3–10 nm, respec-
tively. A different picture is observed at an active com-
Thus, the dependences of the efficiency of nickel
ponent concentration of 9.0% (Figs. 5b, 5d). The his- sulfide catalysts supported on alumina and silica gel on
tograms are bimodal (maxima at 2–4, 5–6 and 3–4, the active component concentration (1.5–9.0%) on
8
–9 nm for alumina and silica gel, respectively) and the supports have been studied using the example of St
asymmetric with a significant broadening to the right. deoxygenation to linear C olefins, which is a com-
17
Therefore, it is impossible to adequately characterize mercially significant reaction. The catalysts supported
them in terms of average values and degrees of disper- on alumina and silica gel have been tested in accor-
sion. However, it is quite obvious that the number of dance with the proposed procedure at a constant
larger particles in the 9.0%Ni catalysts is higher than nickel content in the reactor. Transmission electron
%
1
00
Conversion
Heptadecene selectivity
Heptadecene yield
Heptadecane selectivity
9
0
0
8
7
0
6
5
4
3
2
0
0
0
0
0
1
0
0
1
.5
3.0
4.5
6.0
7.5
9.0
Nickel content in the catalyst, %
Fig. 4. Dependence of the catalytic reaction parameters on metal concentration on the silica gel support (catalyst charge of 1 g,
constant active component content in the reactor).
PETROLEUM CHEMISTRY Vol. 59 No. 6 2019

6
26
KATSMAN et al.
(
a) 6.0 wt % Ni/Al O3
(b) 9.0 wt % Ni/Al O3
2
2
6
w/w
%
Ni/Al O
2 3
9 w/w % Ni/Al O
2 3
4
3
3
2
2
0
5
0
5
0
25
20
15
10
15
1
0
5
0
5
0
50 nm
Size, nm
100 nm
Size, nm
(c) 6.0 wt % Ni/SiO2
(d) 9.0 wt % Ni/SiO2
6
w/w
%
Ni/SiO
2
9 w/w % Ni/SiO
2
3
3
2
2
5
0
5
0
40
35
30
2
5
0
2
15
15
10
10
5
0
5
0
Size, nm
100 nm
Size, nm
50 nm
Fig. 5. Transmission electron microscopy images of the catalysts and particle size distribution histograms.
Table 1. X-ray microdiffraction data for the 6.0 wt % Ni/Al O sample
2
3
Ni3S2,
card 44-1418
NiS,
card 47-1739
NiO,
card 04-0835
Ni,
card 45-1027
IPD, Å
2
.41
.00
.50
.35
.13
.09
2.394
2.056
1.483
–
–
2.030
–
2.400
2.080
1.474
–
–
2.030
–
2
1
1
1.353
1.126
–
–
1
–
–
–
1
1.101
–
–
1.061
–
0.96
0.85
0.80
–
0.957
0.852
0.802
–
–
–
0.804
–
0.808
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THE EFFECT OF THE ACTIVE COMPONENT CONTENT
Table 2. X-ray microdiffraction data for the 9.0 wt % Ni/Al O sample
627
2
3
Ni S ,
card 44-1418
NiS,
card 47-1739
NiO,
card 04-0835
Ni,
card 45-1027
3
2
IPD, Å
2
1
1
1
.32
.92
.37
.10
.97
–
–
–
1.101
0.935
2.350
1.819
1.353
1.098
1.016
–
–
–
1.042
0.957
–
–
–
1.061
1.017
0
Table 3. X-ray microdiffraction data for the 6.0 wt % Ni/SiO sample
2
Ni S ,
card 44-1418
NiS,
card 47-1739
NiO,
card 04-0835
Ni,
card 45-1027
3
2
IPD, Å
3
2
2
.33
.47
.02
–
2.394
–
–
–
–
–
–
1.659
–
–
1.219
1.126
1.016
–
2.400
2.080
–
–
–
2.030
–
–
–
1.244
–
1.017
1
.67
.57
.42
.22
.14
.02
1
1
–
–
1.474
1.253
–
1
1
1
1.254
1.101
1.007
1.042
Table 4. X-ray microdiffraction data for the 9.0 wt % Ni/SiO sample
2
Ni S ,
card 44-1418
NiS,
card 47-1739
NiO,
card 04-0835
Ni,
card 45-1027
3
2
IPD, Å
2
.95
.40
2.850
2.394
–
2.850
–
–
2.400
–
–
–
2
1
.92
.70
.39
1.819
1.659
1.353
–
1
–
–
1.760
–
1
–
1.474
microscopy data have been compared with the test active component content in them and an increase in
results for the catalysts containing 6.0 and 9.0% of
nickel. The results suggest that the higher selectivity of
the alumina-supported catalyst compared with that of
the fraction of large particles on the support surface.
Catalytic runs realized with variation of metal sul-
the silica gel-supported sample can be attributed to fide content on a support other things being equal
the smaller average particle size of nickel sulfides on γ-
revealed the dependency of the catalyst properties
activity, selectivity, particle size of active component
Al O . Apparently, the same factor is responsible for a
2
3
(
relative increase in the oligomerization rate and,
accordingly, a decrease in the selectivity of decarbon-
ylation to olefins in the presence of the silica gel sup-
port. There is a correlation between a decrease in the
etc.) on above variable. It gives an opportunity to opti-
mize this parameter. In addition, it facilitates the cor-
relation of the catalyst efficiency with particle size of
activity of the studied catalysts with an increase in the active component and its surface composition. Conse-
PETROLEUM CHEMISTRY Vol. 59 No. 6 2019

6
28
KATSMAN et al.
quently, one can recommend this plan of catalytic
runs for use in practice.
6. R. Reske, H. Mistry, F. Behafarid, et al., J. Am. Chem.
Soc. 136, 6978 (2014).
7. B. R. Cuenya, Thin Solid Films, 518, 3127 (2010).
. M. Haruta, J. New Mater. Electrochem. Syst. 7, 163
8
FUNDING
(2004).
This work was supported by the Ministry of Educa-
tion and Science of the Russian Federation under a
state task of the Russian Federation, project
no. 10.8454.2017/БЧ.
9
. H. A. Al-Wadhaf, V. M. Karpov, and E. A. Katsman,
Catal. Commun. 116, 67 (2018).
10. A. S. Berenblyum, T. A. Podoplelova, E. A. Katsman,
et al., Kinet. Catal. 53, 595 (2012).
1
1. E. A. Katsman, V. Ya. Danyushevsky, P. S. Kuznetsov,
et al., Pet. Chem. 57, 1190 (2017).
REFERENCES
. Catalytic Process Development for Renewable Materials,
Ed. by P. Imhof and J. C. van der Waal (Wiley–VCH,
Weinheim, 2013).
. A. S. Berenblyum, V. Ya. Danyushevsky, P. S. Kuz-
netsov, et al., Pet. Chem. 56, 663 (2016).
1
2. A. S. Berenblyum, L. I. Lakhman, I. I. Moiseev, et al.,
1
Izv. Akad. Nauk SSSR, Ser. Khim., No. 6, 1287 (1975).
13. E. A. Katsman, O. B. Vetrova, and F. D. Klebanova,
Khim. Prom-st., No. 4, 210 (1998).
2
3
4
14. J. D. Hanawalt, H. W. Rinn, and L. K. Frevel, Ind.
Eng. Chem. 10, 457 (1938).
. K. Bergamaski, A. LN. Pinheiro, E. Teixeira-Neto, and
F. C. Nart, J. Phys. Chem. B 110, 19271 (2006).
15. V. I. Bukhtiyarov and M. G. Slin’ko, Russ. Chem. Rev.
70, 167 (2001).
. O. M. Wilson, M. R. Knecht, J. C. Garcia-Martinez,
and R. M. Crooks, J. Am. Chem. Soc. 128, 4510 16. V. Ya. Danyushevsky, V. Yu. Murzin, P. S. Kuznetsov,
(2006).
et al., Russ. J. Phys. Chem. A 92, 66 (2018).
5
. W. P. Zhou, A. Lewera, R. Larsen, et al., J. Phys.
Chem. B 110, 13393 (2006).
Translated by M. Timoshinina
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