1070-4272/02/7507-1104$27.00C2002 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 75, No. 7, 2002, pp. 1104 !1107. Translated from Zhurnal Prikladnoi Khimii, Vol. 75, No. 7,
2002, pp. 1121!1124.
Original Russian Text Copyright + 2002 by Saurambaeva, Sembaev.
Effect of Reaction Medium on the Composition
of Vanadium!Titanium Catalyst in Oxidative Ammonolysis
L. I. Saurambaeva and D. Kh. Sembaev
Bekturov Institute of Chemical Sciences, Almaty, Kazakhstan
Received July 25, 2001; in final form, January 2002
Abstract-The influence exerted by the concentration of alkylpyridines on the chemical composition of
a vanadium!titanium catalyst under oxidative ammonolysis conditions was subjected to a comparative study.
In the course of catalysis, a catalyst undergoes
transformations as a result of its interaction with reac-
tants. The steady-state composition of the catalyst,
which determines its activity and selectivity, is
formed under the influence of the reaction medium.
Under the conditions of oxidative ammonolysis, as
also in other reactions, the extent to which the medi-
um affects the catalyst depends on numerous factors,
among which the relative amounts of air (oxidizing
agent) and an organic compound are important. The
change in the composition of a catalyst and, in par-
ticular, of a vanadium oxide catalyst modified with
oxides of titanium(IV), tin(IV), and other metals is
due to reduction of vanadium(V) oxide. For example,
it has been shown  that vanadium(V) oxide in
a vanadium3titanium catalyst is reduced under the
action of the reaction medium, with the result that
the ratio of V
to the VO
which determines the activity and selectivity of the
catalyst, also changes.
The extent to which the reaction medium affects
a catalyst depends on the degree of conversion of
an organic substance, which is determined by the
nature of this substance . Therefore, in selecting
a catalyst and determining the optimal conditions
of the oxidative process, account should be taken
of the catalyst composition, which is formed in the
course of catalysis under the influence of the reaction
medium and ensures the stability of the catalyst opera-
This study was aimed to reveal how the structure
of alkylpyridines affects the composition and, con-
sequently, catalytic properties of the vanadium3titani-
um oxide catalyst.
The starting 2-methyl-5-ethylpyridine (MEP) and
b-picoline of pure grade contained no less than 98%
Experiments on oxidative ammonolysis of alkyl-
pyridines were performed on a flow-through installa-
tion with the reaction tube (length 130 mm, diameter
20 mm) made of quartz glass. The reaction products
were absorbed with water and analyzed chromato-
graphically with a flame-ionization detector on a col-
umn packed with 15% Carbowax 20M on Chromaton
N-AW (0.1630.20 mm). The analytical procedure
with programmed heating from 100 to 180oC at a rate
of 10 deg min
enabled determination of pyridine,
3-methylpyridine, 2-methyl-5-ethyl-, 2-methyl-5-
vinyl-, 3-cyano-, 2-cyano-5-ethyl-, and 2-cyano-5-
vinylpyridines. 2,5-Dicyanopyridine was determined
polarographically after its conversion to isocin-
chomeronic acid by base hydrolysis.
Carbon oxides were analyzed chromatographically
with a heat conductivity detector.
The vanadium3titanium catalysts were prepared
by mixing vanadium(V) and titanium(IV) oxides of
analytically pure grade with subsequent compaction of
the stock into pellets and calcination at 800oC in air
flow for 2 h.
X-ray phase analysis of the catalysts was carried
out on a DRON-0.5 diffractometer with CuK
tion. The content of vanadium(V) oxide in the cata-
lysts was determined by IR spectroscopy . Samples
for analysis were prepared as KBr pellets.
The oxidative ammonolysis of MEP on a vana-
dium3titanium oxide catalyst with the molar ratio