ISSN 0965ꢀ5441, Petroleum Chemistry, 2013, Vol. 53, No. 6, pp. 412–417. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © I.G. Korosteleva, N.A. Markova, N.V. Kolesnichenko, N.N. Ezhova, S.N. Khadzhiev, N.I. Trukhmanova, 2013, published in Neftekhimiya, 2013, Vol. 53, No. 6,
pp. 461–466.
Catalytic Synthesis of Propylene Carbonate from Propylene Oxide
and Carbon Dioxide in the Presence of Rhodium Complexes Modified
with Organophosphorus Ligands and Chitosan
I. G. Korosteleva, N. A. Markova, N. V. Kolesnichenko, N. N. Ezhova,
S. N. Khadzhiev, and N. I. Trukhmanova
Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russia
eꢀmail: korosteleva@ips.ac.ru
Received November 7, 2012
Abstract—The reaction between CO2 and propylene oxide to produce propylene carbonate in the presence
of rhodium complexes modified with organophosphorus ligands and chitosan has been studied. Highly effecꢀ
tive catalysts mediating the reaction with almost a 100% yield and 100% selectivity have been prepared using
rhodium compounds modified with triphenylphosphine and chitosan.
DOI: 10.1134/S0965544113060108
Propylene carbonate is an important intermediate than in the case of catalysis by quaternary ammonium
in the chemical industry; it is strongly sought for by a salts [4]. The best results were obtained for the reacꢀ
number of advanced technologies. It is used as a coolꢀ tion conducted in an ionic liquid (in cetyltrimethyꢀ
ant in booming laser technology and as a precursor for lammonium chloride) using a ruthenium chloride
the synthesis of monomers, polymers, plasticizers, bipyridine complex as a catalyst [3]. The complete
modifiers, plant protection agents, etc. Furthermore, conversion of propylene oxide is achieved at 3.0 MPa
it is a starting material in the synthesis of 1,2ꢀpropyꢀ and 75
lene glycol.
At present, the demand for this chemical material
is tens of tons per year, and this figure will increase in
the coming years.
°C within 4 h.
It is of great interest to study the catalytic properꢀ
ties of rhodium complexes in this reaction, because it
is known from [5, 6] that rhodium exhibits a high
activity in syntheses involving СО2. Modification of
rhodium complexes with ligands of different nature
can lead not only to a significant change in the dynamꢀ
ics of the process and the composition of the reaction
products, but also to an increase in the lifetime of the
catalyst. Therefore, the aim of this study was to examꢀ
ine the interaction between propylene oxide and СО2
in the presence of a catalyst system based on rhodium
complexes and search for ways to improve its effiꢀ
ciency.
Propylene carbonate is produced from propylene
oxide and СО2 through the reaction:
CO +
2
CH3 CH CH2
O
CH3 CH
O
CH2
O
C
O
The synthesis is conducted at a high pressure of СО2
(5.0–10.5 MPa) and high temperatures (100–200
°C)
in the presence of quaternary ammonium salts and
alkali metal halides (commercial versions of Jefferson
Chemical Company, BASF (Ludwigshafen, Gerꢀ
many) [1], and ChimeiꢀAsahi Corporation (Taiwan)
[2]). The catalyst (quaternary ammonium salt) can be
reused; however, it is necessary to feed it with a fresh
batch in an amount of 30%, and the purification of the
product from the spent catalyst is fraught with the forꢀ
mation of large amounts of wastewater.
EXPERIMENTAL
The rhodium precursors of the catalyst system were
rhodium chloride RhCl3, complex RhCl(PPh3)3, carꢀ
bonylꢀcontaining
acetylacetonate
complex
acacRh(CO)2, and dirhodium tetracarbonyl dichloride
Rh2Cl2(CO)4. The rhodium precursors were modified
with organophosphorus ligands and chitosan.
The series of organophosphorus ligands, along with
Recently, many studies focused on the use of comꢀ conventional triphenylphosphine (the P–C bond),
plexes of transition metals, in particular ruthenium, was composed of a cyclic phosphite ligand (the P–O–
for this process have been carried out [3, 4]. In the C bond) and phosphonite (containing both the P–C
presence of ruthenium complexes, the synthesis of and P–O–C bond). Chitosan was used as a nitrogenꢀ
propylene carbonate occurs under milder conditions containing ligand.
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