Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 11, pp. 1691−1701.
Pleiades Publishing, Ltd., 2013.
Original English Text © Hoang Kim Bong, Hoang Huu Binh, I.I. Kurlyandskaya, A.N. Nyrkova, D.I. Yamandii, O.N. Temkin, 2013, published in Zhurnal
Prikladnoi Khimii, 2013, Vol. 86, No. 11, pp. 1740−1751.
AND SEPARATION PROCESSES
Regularities of Adsorption of Zinc Acetate from Aqueous
Solutions onto the Surface of Modiﬁ ed Activated Carbons
Hoang Kim Bong, Hoang Huu Binh,
I. I. Kurlyandskaya, A. N. Nyrkova, D. I. Yamandii, and O. N. Temkin
Lomonosov Moscow State University of Fine Chemical Technologies, Moscow, Russia
Received July 20, 2010
Abstract—The dependence of the characteristics of Zn(OAc)
/С catalysts for vinyl acetate synthesis on the solu-
tion circulation rate, on the temperature and initial concentration of zinc acetate solution, and on the procedures
for modiﬁ cation of activated carbons with oxidants was studied with the aim to achieve uniform distribution of
the supported active component (zinc acetate). Oxidation of activated carbons with hydrogen peroxide and nitric
acid increases the adsorption rate and the amount of adsorbed zinc acetate. Treatment of the support with acetic
acid leads to an increase in the adsorption capacity for zinc acetate, to more uniform distribution of the active
component over the surface, and to enhancement of the catalyst activity. The hydrodynamic regime of stirring in
the two-phase system consisting of the support and zinc acetate solution is an important factor determining the
activity and stability of the zinc acetate catalyst for vinyl acetate synthesis.
The adsorption properties of activated carbons (ACs)
with respect to organic substances  and metal salts [2,
3] are often difﬁ cult to explain within the framework of
known concepts of physical and chemical adsorption. The
relationships of the adsorption process, as demonstrated
by the examples of HgCl
[4, 5] and Zn(OAc)
determined by the AC nature, by the conditions for
deposition of the active component (hydrodynamic
regime), and by the procedure for modiﬁ cation of the
AC surface .
Because ACs are widely used as supports in industrial
/C, synthesis of vinyl chloride (VC) [8–
/С, synthesis of vinyl acetate (VA) [10–12];
Pd/C, hydrogenation processes [13, 14]; PdCl
CO oxidation } and the activity and operation life
(stability) of catalysts strongly depend on the procedure
for preparing supported catalysts, it is very important to
elucidate the speciﬁ c features of the adsorption of salts
on ACs as a step of the catalyst preparation process. It
should be noted that the kind of the kinetic model of the
process (VA synthesis) can itself depend on the catalyst
preparation procedure .
This study deals with the relationships of Zn(OAc)
adsorption onto ACs of AGN-2 and AHN-3 grades
(prepared from carbon-containing raw materials by
chemical activation), treated with nitric acid, hydrogen
peroxide, or acetic acid, under the conditions of intense
circulation of the salt solution through a bed of the
support dispersed in the liquid phase (ﬂ uidized bed).
Some properties of ACs treated with acetic acid have been
described previously [17, 18]. Some most characteristic
relationships are given also in this paper for comparison
with AC samples modiﬁ ed with nitric acid and hydrogen
Treatment of activated carbons with hydrogen
peroxide. AGN-2 activated carbon with the particle
size of 1–5 mm was preliminarily treated in succession