Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 11, pp. 1741−1745.
Pleiades Publishing, Ltd., 2013.
Original English Text © M.B. Alekhina, M.V. Papkova, T.V. Kon’kova, B.I. Kutepov, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 11,
Catalysts Based on NaY Zeolite for Oxidative
Destruction of Organic Azo Dyes
M. B. Alekhina, M. V. Papkova, T. V. Kon’kova, and B. I. Kutepov
D.I. Mendeleev Russian Chemical-Technological University, Moscow, Russia
Institute of Petrochemistry and Catalysis, Russian Academy of Sciences, Ufa, Russia
Received April 5, 2013
Abstract—Samples of catalysts containing Ag
cations were prepared on the basis of NaY granulated
synthetic zeolite without binders by the ion-exchange method with the subsequent thermal treatment at 350−500°С.
It was found that CoNaY samples are most catalytically active in the process of carmoisine oxidation by hydrogen
peroxide in a weak alkaline medium (pH 8.5).
Production of dyes, ﬁ nishing materials, and textile
industry are sources of injection of waste water polluted
by dyes into the environment. It stipulates necessity of
development of technologies for complete destruction of
such waste water or turning them into products, which
can be detoxiﬁ ed biologically .
One of the most spread homogeneous catalytic
systems offered for the destruction of organic dyes in
wastewater is Fenton’s reagent (Fe
essential disadvantages consist in impossibility of its
regeneration, narrow рН limits for oxidative conversions
of the above-mentioned substances, and the necessity of
extracting metal ions from treated water. The application
of heterogeneous catalysts, in particular zeolites, which
can be readily isolated from water, makes it possible to
solve the majority of the listed problems.
As a result of the hydrogen peroxide reaction with
transition metal ions containing in a catalyst, active
hydroxyl radicals initiating radical chain reactions are
formed. It results in the oxidative destruction of organic
compounds. Transition metals are ﬁ xed in zeolite concavi-
ties. Systems containing iron and copper ions are the most
studied among zeolite catalysts [2–6].
The aim of this work was to prepare samples of cobalt-
and silver-containing catalysts based on zeolite Y and to
determine their activity and also stability at the catalytic
oxidation of the organic dye carmoisine (a synonym azo-
rubine) by hydrogen peroxide. Carmoisine belongs to the
group of organic azo dyes, it contains various functional
groups capable to enter into redox reactions:
Granular zeolite NaY without binders (NaY-BS) with
the mole ratio SiО
4.8 was used in the work as
a catalyst support. Its granules represent mechanically
strong shanks of 1.7 mm in diameter, 90–95% of which
consists of aggregates of zeolite Y crystals in the Na-
form . Bulk weight of the zeolite after dehydration at