ISSN 0036-0244, Russian Journal of Physical Chemistry A, 2017, Vol. 91, No. 6, pp. 1005–1009. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © J.I. Mirzai, P.A. Nadirov, A.D. Velieva, V.G. Muradkhanli, 2017, published in Zhurnal Fizicheskoi Khimii, 2017, Vol. 91, No. 6, pp. 952–956.
CHEMICAL KINETICS
AND CATALYSIS
Oxidation of Ethanol on NaX Zeolite Modified
with Transition Metals
J. I. Mirzai, P. A. Nadirov*, A. D. Velieva, and V. G. Muradkhanli
Azerbaijan State Oil and Industrial University, Baku, AZ100 Azerbaijan
*е-mail: parviznadirov@rambler.ru
Received May 23, 2016
Abstract—NaLaX, NaX + Co, and NaPdX catalysts are synthesized by modification of NaX zeolite with
transition metals (La, Co, Pd). The activity of the prepared materials in catalytic ethanol oxidation is studied
in the temperature range of 423–723 K. It is shown that NaPdX and NaX + Co accelerate the reactions of
partial and complete oxidation of ethanol as the temperature rises. NaLaX accelerates both intramolecular
and intermolecular dehydration of alcohol. It is shown that the NaPdX (1.0% Pd) sample has the highest
activity in the complete oxidation of alcohol with the formation of CO2.
Keywords: catalyst, zeolite, oxidation, alcohol
DOI: 10.1134/S0036024417060164
INTRODUCTION
every 6 h. The solution was filtered, and the precipitate
was dried. NaPdX catalyst was reeduced with hydro-
gen at 573 K. Pd2+ ions that had entered the zeolite
structure through ionic exchange were reduced to
their neutral state (Pd0). NaPdX catalysts containing
Pd0 in amounts of 0.1, 0.5, and 1.0% were prepared in
this manner. NaLaX catalyst samples containing La3+
in amounts of 1.0, 5.0, and 10.0% were also prepared
via ion exchange.
NaX + Co catalyst was prepared via impregnation
of NaX zeolite with a solution of cobalt nitrate. The
sample was dried at 373 K until there was complete
cleavage of the impregnated salt. The resulting mass
was calcined at 573 K and then kept at 823 K for 10 h.
Zeolite catalysts with 1.0, 2.5, 5.0, and 10.0% cobalt
were thus obtained by means of impregnation. The
resulting catalysts were pressed into tablets, which
were crushed into particles 1–2 mm in size. The cata-
lysts were then examined via X-ray diffraction (see
Fig. 1).
Though there have been many studies of the cat-
alytic conversion of alcohols, their conversion on
zeolite-containing catalysts in an oxidative environ-
ment is less studied. By modifying synthetic NaX
zeolite with transition metals (La, Co, Pd), we
obtained NaLaX and NaPdX catalysts (through ion
exchange), and NaX + Co (through impregnation).
Their activity in the oxidation of ethanol was stud-
ied in the temperature range of 423–723 K. All of
the synthesized catalysts, including the initial NaX,
displayed some activity in the process. Our studies
showed that introducing transition metals into the
initial zeolite substantially affects its catalytic prop-
erties. This effect is due to the nature of the metal
and its position in the zeolite structure. In the con-
version of ethanol, concurrent and consecutive
series of reactions proceed on the catalysts: the
intramolecular and intermolecular dehydration of
alcohol, its partial and complete oxidation.
The activity of the catalysts was tested in the pro-
cess of ethanol oxidation in air [2–7]. The process was
conducted in a tubular flow reactor in the temperature
range of 423–723 K. The volume of the catalyst was
5 mL, and the feed flow rate was 2400 h−1. The ratio of
ethanol to air in the gas mixture was 1 : 10. The initial
materials and the reaction products were analyzed by
means of chromatography.
EXPERIMENTAL
Catalysts based on NaX zeolite and transition met-
als Pd, La, and Co were prepared by means of ion
exchange and impregnation [1]. Catalysts containing
Pd and La were obtained via ion exchange, and the
catalyst containing Co was obtained via impregnation.
Ion exchange was conducted by adding solutions of
the corresponding metal salt (PdCl2, LaCl3) with con-
centrations of 0.1 N to NaX, followed by continuous
stirring at a temperature of 80°C. The process was
RESULTS AND DISCUSSION
Our aim was to study the activity of catalysts syn-
conducted over 36 h with the solution being replaced thesized by different means in the processes of partial
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