ISSN 1070-4272, Russian Journal of Applied Chemistry, 2016, Vol. 89, No. 7, pp. 1109−1118. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © A.V. Smirnov, M.A. Panteleyev, V.V. Krivetskiy, A.M. Gaskov,
2016, published in Zhurnal Prikladnoi Khimii, 2016, Vol. 89, No. 7, pp. 916−926.
ORGANIC SYNTHESIS AND INDUSTRIAL
Catalytic Oxidation of Unsymmetrical
Dimethylhydrazine on Pt/SiO
A. V. Smirnov*, M. A. Panteleyev, V. V. Krivetskiy, and A. M. Gaskov
Moscow State University, Moscow, Russia
Received May 18, 2016
Abstract—Speciﬁ c features of oxidation of unsymmetrical dimethylhydrazine on a Pt-containing catalyst were
studied. The temperature dependence of the unsymmetrical dimethylhydrazine conversion was determined, and the
main intermediate and ﬁ nal reaction products were identiﬁ ed. Platinum behaves in the process as a multifunctional
catalyst participating in dehydrogenation, hydrogenolysis, and oxidation. A new method was suggested for detecting
unsymmetrical dimethylhydrazine in air. It consists in catalytic conversion of unsymmetrical dimethylhydrazine
and detection of the nitrogen dioxide formed with semiconductor gas sensors. The method was successfully used
for detecting unsymmetrical dimethylhydrazine in air at concentrations in the range 0.1–10 mg m
Unsymmetrical dimethylhydrazine (UDMH) is
widely used as propellant. Extremely high toxicity of
this compound for humans (hazard class 1) makes urgent
the problems of its detection and neutralization in air at
spillages and other emergency situations, and also of uti-
lization of excessive UDMH amounts . The UDMH
transformations are very diverse , and many products
of its decomposition are also extremely toxic. Therefore,
pathways of directional UDMH conversion are of much
practical interest. One of the ways of UDMH utiliza-
tion is its catalytic oxidation with atmospheric oxygen.
Various materials were tested as catalysts of this pro-
cess, with the catalytic system 30–33% Ir/Al
, used in
space engineering , being the most studied; metal ox-
ides, noble metals, silicon nitride, and other compounds
were also used as UDMH oxidation catalysts [4, 5]. Al-
though studies in this ﬁ eld are already being performed
for several decades, the mechanism of the catalytic oxi-
dation of UDMH has not been reliably determined yet.
As a rule, suggested mechanisms are very schematic and
do not take into account speciﬁ c features of operation of
various catalytic phases.
Platinum applied onto a support is an active catalytic
component in oxidation of many organic compounds.
Ismagilov et al.  studied the oxidative conversion of
UDMH on 0.64% Pt/Al
catalyst. This system exhib-
its high catalytic activity in UDMH conversion, but its
speciﬁ c feature is increased formation of nitrogen oxides.
The cause of differences in the UDMH transformation
products on this and other catalysts was not revealed.
This study was aimed at ﬁ nding the conditions and
main pathways of UDMH oxidation on Pt-containing
catalysts to perform the direct conversion of UDMH to
the environmentally safest products. For this purpose,
we chose a support inert toward UDMH, prepared a
catalyst with platinum supported on it, and used this
catalyst in experiments on determining the inﬂ uence of
temperature and oxygen content in the system on the
UDMH conversion and on the composition of the cata-
lytic oxidation products.
Aluminum oxide with the speciﬁ c surface area of
and silochrom (silica with the speciﬁ c surface
area of 110 m
, hereinafter designated as SiO
were tested as supports for preparing the Pt-containing