1130
CHUDAKOVA et al.
Table 1. Concentrations of salts in precursor aqueous solu-
thesis temperature. Prior to catalytic runs reductive
activation in situ was performed under the following
conditions: hydrogen, 20 L/h; pressure, 50 МРа; tem-
perature, 350°С; and time, 1 h.
tions during formation of catalytic slurries
Concentration
Concentration
of Co(NO3)2, g/L
Sample
of Cu(NO3)2, g/L
The feed syngas and the gaseous synthesis products
were analyzed by gas-solid chromatography on a
Kristallyuks-4000 chromatograph equipped with a
thermal conductivity detector using helium as a car-
rier. CO and N2 were separated under the isothermal
regime at a temperature of 80°С using a 3 m × 3 mm
column packed with CaA molecular sieves. СО2 and
hydrocarbons С1–С4 were separated using a Haye
Sep R (3 m × 3 mm) packed column with temperature
programmed heating from 80 to 200°С at a rate of
8°С/min.
Sample 1
Sample 2
53
186
19
65
consequence, the presence of sulfur-containing com-
pounds in reaction products [5];
(3) modified Fischer–Tropsch catalysts (Co, Fe)
show high selectivity for alcohols. They suffer from
low stability, which may be considerably improved by
selecting precursors and catalyst formation methods
[6, 7].
A mixture of liquid hydrocarbons was analyzed by
gas-liquid chromatography on a Kristallyuks-4000M
chromatograph equipped with a flame ionization
detector and a 50 m × 0.32 mm OV-351 capillary col-
umn. The flow rate of helium, hydrogen, and air was
30, 25, and 250 mL/min, respectively. The tempera-
ture programmed regime was as follows: 50°С (2 min),
heating from 50 to 260°С at a rate of 6°С/min, heating
from 260 to 270°С at a rate of 5°С/min, and holding at
270°С for 10 min. Oxygen-containing products con-
tained in the aqueous phase were analyzed in the fol-
lowing chromatographic mode: the flow rate of
helium, hydrogen, and air was 20, 25, and
250 mL/min, respectively. A 50 m × 0.32 mm ×
0.50 μm HP-FFAP capillary column (nitrotereph-
thalic acid-modified poly9ethylene glycol)) was used
for analysis. The sample volume was 0.3 μL. The tem-
perature programmed regime was as follows: 70°С
(8 min), heating from 70 to 110°С at a rate of
Thus, the modified catalysts of methanol synthesis
and Fischer–Tropsch synthesis are the most promis-
ing in the production of alcohol mixtures; Cu–Co cat-
alysts are of particular interest among them because
they combine properties of both types of catalytic sys-
tems.
Copper-containing catalysts for methanol synthe-
sis in the slurry reactor were synthesized [8], and
nanosized catalytic suspensions exhibited high activity
in CO hydrogenation in situ in a medium of the slurry
reactor were prepared [9]. This paper concerns the
effect of active metal precursor concentration on the
physicochemical and catalytic properties of Cu–Co-
containing nanosized slurries formed immediately in
the medium of the slurry reactor.
EXPERIMENTAL
Catalytic systems were formed by the method of 10°С/min, heating from 110 to 220°С at a rate of
drop thermolysis, which consisted in a slow addition 15°С/min, and holding at 220°С (10 min). Quantita-
of the aqueous solution of copper and cobalt nitrates tive calculations were performed by the internal stan-
to the molten paraffin P-2 (a mixture of hydrocarbons dard method using isobutyl alcohol as a standard.
С16–С32) under continuous stirring in an inert
The activity of catalytic systems was assessed from
medium. The calculated amounts of Cu(NO3)2 · 3H2O
the value of CO conversion. The product selectivity
(Acros Organics, 99%) and Co(NO3)2 · 6H2O (Acros
Organics, 99%) were dissolved in distilled water to
was calculated as the ratio of the amount of carbon
consumed in the formation of component to the total
obtain solutions with different salt concentrations
amount of carbon in the reacted CO.
(Table 1). The weight ratio of Cu : Co was 3 : 1 at a total
metal concentration of 20 wt %.
Reflection IR spectra were measured on a HYPE-
RION-2000 IR microscope coupled with a Bruker
IFS-66 ν/s FTIR spectrometer (600–4000 cm–1).
The particle size of the synthesized samples was
determined by dynamic light scattering on a Malvern
Zetasizer Nano ZS instrument. Sample preparation
was conducted by dissolving 0.01 g of the average cat-
alytic slurry sample in 10 mL of n-hexane containing
5 wt % surfactant (sodium dioctyl sulfosuccinate).
Catalytic tests were run on an autoclave-type unit
equipped with a mechanical stirrer in the gas flow
mode at a pressure of 5 MPa and a syngas space veloc-
ity (molar ratio of СО : Н2 = 1 : 2) of 10 L/h. The dura-
Magnetometry measurements were carried out in
situ on a setup based on a vibrating magnetometer at
room temperature [10]. The sample weight was 20 mg.
Magnetic field strength was set by a GPR-30H10D dc
source in the range from –0.6 to 0.6 T. Magnetic
induction was measured with the aid of an RSh1-10
magnetic induction device. The vibration amplitude
of the measuring cell in the vertical plane was main-
tion of the isothermal regime was 12 h. Sampling of tained constant at a level of 0.5 mm at a frequency of
the gas and liquid products was performed at each syn- 30 Hz. Signals were registered at a frequency of 1 Hz.
PETROLEUM CHEMISTRY
Vol. 60
No. 10
2020
Bondarenko, G. N.
