ISSN 0036ꢀ0236, Russian Journal of Inorganic Chemistry, 2011, Vol. 56, No. 3, pp. 335–337. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © A.A. Artyukhov, Ya.M. Kravets, A.A. Artyukhov, A.P. Babichev, A.V. Ryzhkov, 2011, published in Zhurnal Neorganicheskoi Khimii, 2011, Vol. 56, No. 3,
pp. 377–379.
SYNTHESIS AND PROPERTIES
OF INORGANIC COMPOUNDS
Synthesis of Water and Molecular Oxygen Highly Enriched
in 17O and 18O Isotopes from Carbon Oxides
A. A. Artyukhov, Ya. M. Kravets, A. A. Artyukhov, A. P. Babichev, and A. V. Ryzhkov
Kurchatov Institute, Moscow, Russia
Received August 3, 2009
Abstract—The reaction of carbon oxides and hydrogen in the presence of the Raney nickel catalyst has been
used for water synthesis. A procedure has been developed for the recovery and collection of the synthesized
water with minimal losses and without deteriorating the 17O or 18O isotope enrichment as compared to the
initial CO2 and CO. The recovery of oxygen with high concentrations of 17O and 18O isotopes is based on the
reaction of xenon difluoride with water. The yield based on oxygen achieves 99% without reduction of isotope
enrichment, which is confirmed by massꢀspectral measurements of oxygen isotope concentrations in the iniꢀ
tial reagents and final reaction products.
DOI: 10.1134/S0036023611030053
In some cases it appears necessary to obtain water a hydrogen flow with a pressure of ~101 kPa and a flow
17
18
or molecular oxygen enriched with O and O isoꢀ rate of 5 nL/h for 3 h in order to remove trace oxygen
topes from carbon oxides, which are produced in isoꢀ from the catalyst. Highꢀpurity hydrogen applied in
tope separation processes.
electronic industry was used in this study.
17
Carbon oxides with high concentrations of O or
18O are not always applicable as the carriers of these
isotopes. Most frequently, 18Оꢀenriched oxygen is used
in medicine as a constituent of water.
The carbon oxide samples used having various conꢀ
centration of carbon and oxygen isotopes were the
products of the separation of carbon and oxygen isoꢀ
topes and were purified by lowꢀtemperature vacuum
distillation. The isotope composition of the initial
reagents and reaction products was monitored by mass
spectrometry using a MIꢀ1201V mass spectrometer
equipped with an ion source having electron impact
ionization and a system for automatic recording and
treating mass spectra. The error of determination of
Dioxygen enriched in 17О or 18O isotopes is used in
various physical and physicochemical studies. Taking
into account the existing demand and high cost of
these isotopes (especially of 17O), it seems to be imporꢀ
tant to develop procedures for the recovery of isotopeꢀ
enriched oxygen from carbon oxides with minimal
losses and without decreasing the degree of isotope
enrichment. In addition, such a procedure is interestꢀ
ing in the context of the analysis of the isotope compoꢀ
sition of carbon oxides subjected to the separation of
isotopes by a centrifugal, laser, or rectification
method.
the concentrations of molecules ( ) was as follows:
δ
0.05% for 1.5–3.0%, 0.1% for 3.0–10.0%, and 0.2%
for 10.0–90.0%.
Oxygen was recovered from the synthesized water
samples either by electrolysis with a miniature memꢀ
brane electrolyzer or by using the reaction between
water and xenon difluoride (1). Xenon difluoride was
obtained as a result of combustion of xenon in fluoꢀ
rine, and then it was purified from admixtures of
xenon tetrafluoride, hydrogen fluoride, and some
metal fluorides in order to provide the purity level
above 99.99% according to the results of IR analysis
(Bruker Equinox 55 Fourier spectrometer with multiꢀ
pass cell) and elemental analysis (ICPꢀAES).
The synthesis of water from carbon oxide was based
on the reaction of carbon oxides with hydrogen in the
presence of nickel catalysts used for hydration [1].
The recovery of dioxygen from water is based on the
reaction between xenon difluoride and water [2]:
1
2
(1)
XeF2 + H2 O → O2 + Xe + 2HF.
Gas pressures and flow rates were measured using
SapfirꢀDA pressure gages with 0.25 precision and
working ranges of 0–10 kPa and 0–100 kPa.
Temperature was measured and controlled by temꢀ
perature sensors equipped with Chromel–Alumel
thermocouples as the sensitive element.
OBJECTS AND METHODS
Skeleton nickel (Raney nickel) produced by Merck
was used as the catalyst. Before the conversion of carꢀ
bon oxides into water, the catalyst placed into herꢀ
metic reactor was carefully dehumidified by vacuum
distillation at 100
Then, the reactor was heated to 200
°
С
to a residual pressure of 0.13 Pa.
All weighing operations were performed with 10ꢀ
and purged with mg precision on a Mettler PM6100 balance.
°
С
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