Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 7, pp. 1182−1188.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
T.L. Rakitskaya, V.O. Vasilechko, T.A. Kiose, G.V. Grishchuk, V.Ya. Volkova, 2010, published in Zhurnal Prikladnoi Khimii, 2010,
Vol. 83, No. 7, pp. 1079−1084.
INORGANIC SYNTHESIS AND INDUSTRIAL
Adsorption-Desorption Properties of Bazalt Tuff and Catalytic
Activity of Acido Complexes of Palladium(II) and Copper(II)
in the Reaction of Carbon(II) Oxide Oxidation with Oxygen
T. L. Rakitskaya, V. O. Vasilechko, T. A. Kiose, G. V. Grishchuk, and V. Ya. Volkova
Mechnikov National University, Odessa, Ukraine, Franko National University, L’vov, Ukraine
Received December 7, 2009
Abstract—Desorption of palladium(II) and copper(II) from the K
–KBr/Н-BT-6 catalysts, in
which bazalt tuff from various deposits subjected to acid modiﬁ cation is used as carrier, was studied.
The nature of the carrier [SiO
or TZK-М tripoli] affects not only the activity of the
Cu(II)–Pd(II)–KBr catalyst but also its stability in
a steady-state oxidation of carbon(II) oxide with oxygen
. On anchoring of palladium(II) and copper(II) acido
complexes to Al
(MCMK), the catalysts
exhibiting high activity in the initial period of the reac-
tion losses quickly its ability to CO oxidation and, in
the case of Al
, no steady-state mode is established
owing to a clear predominance of the reaction of Pd(II)
recovery to Pd
. Only in the case of TZK-M tripoli
containing 99.8% of amorphous silica and obtained by
special treatment of a natural mineral, the catalyst of
a CO oxidation exhibiting the high activity and stability
is formed .
The mechanism of the formation of surface complexes
and the bond strength of each metal ion to the surface of
the carrier are the essential factors affecting the activity of
anchored acido complexes of palladium(II) and copper(II)
in the reaction of CO oxidation with oxygen . In the
case of TZK-M tripoli, palladium(II) is weakly anchored
to the carrier surface and easily desorbs at a quantitative
level with cold water, whereas the portions of weakly
and strongly anchored copper(II) are nearly the same.
Evidently, the character of the metal ion bonds to the
functional group of the carrier determines the possibility
of formation of the surface bimetallic complex Cu(II)–
Pd(II), which has high activity and stability in the reaction
of CO oxidation.
In terms of solving the problems about the rational
use of natural resources, it was demonstrated that natu-
ral aluminosilicates may be the promising carriers of
palladium(II) and copper(II) acido complexes catalyzing
a low-temperature CO oxidation with air oxygen [3, 4].
In studying the natural sorbents, for example basalt tuff
(BT), as a carrier of acido complexes, it was found that
the copper(II) adsorption from a solution containing
), and KBr is selective and
that, contrary to palladium(II), copper(II) is anchored
reasonably strong to the carrier surface [3–6].
For bazalt tuffs of various origins, the chemical
composition and the mass ratio of the major phases
(clinoptilolite, mordenite, and montmorillonite) are dif-
ferent . The differences should be reﬂ ected in their
adsorption-desorption properties with respect to metal
ions. It should be expected that, owing to a variety and
diversity of the adsorption centers [=AlOH, ≡SiOH, and
Si(OH)Al], palladium(II) and copper(II) with the carrier
surface form bonds of varied strength. This will certainly
affect the catalytic activity of bimetallic complexes in the
reaction of CO oxidation with oxygen.
The study is aimed at establishing the correlation be-
tween the adsorption-desorption properties of the basalt
tuff samples obtained from different deposits and sub-
jected to acid modiﬁ cation and the activity of Cu(II) and
Pd(II) acido complexes anchored on them in the reaction
of CO oxidation with oxygen.