METHOD AND CATALYST SYSTEM FOR PRODUCING
AROMATIC CARBONATES
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a method and catalyst system for producing
aromatic carbonates and, more specifically, to a method and catalyst system for
producing diaryl carbonates through the carbonylation of aromatic hydroxy
compounds.
2. Discussion of Related Art:
Aromatic carbonates find utility, inter alia, as intermediates in the preparation of
polycarbonates. For example, a popular method of polycarbonate preparation is the
melt transesterification of aromatic carbonates with bisphenols. This method has been
shown to be environmentally superior to previously used methods which employed
phosgene, a toxic gas, as a reagent and chlorinated aliphatic hydrocarbons, such as
methylene chloride, as solvents.
Various methods for preparing aromatic carbonates have been previously described in
the literature and/or utilized by industry. A method that has enjoyed substantial
popularity in the literature involves the direct carbonylation of aromatic hydroxy
compounds with carbon monoxide and oxygen. In general, practitioners have found
that the carbonylation reaction requires a rather complex catalyst system. For
example, in U.S. Patent No. 4,187,242, which is assigned to the assignee of the
present invention. Chalk reports that a carbonylation catalyst system should contain a
Group VIII B metal, such as ruthenium, rhodium, palladium, osmium, iridium.
platinum, or a complex thereof. Further refinements to the carbonylation reaction
include the identification of organic co-catalysts, such as terpyridines,
phenanthrolines, quinolines and isoquinolines in U.S. Patent No. 5,284,964 and the
use of certain halide compounds, such as quaternary ammoniiun or phosphonium
halides in U.S. Patent No. 5,399,734, both patents also being assigned to the assignee
of the present invention.
The economics of the carbonylation process is strongly dependent on the
number of moles of aromatic carbonate produced per mole of Group VIII B metal
utilized (i.e. "catalyst turnover"). Consequently, much work has been directed to the
identification of efficacious inorganic co-catalysts that increase catalyst turnover. In
U.S. Patent No. 5,231,210, which is also assigned to General Electric Company,
Joyce et al. report the use of a cobalt pentadentate complex as an inorganic co-catalyst
("lOCC"). In U.S. Patent No. 5,498,789, Takagi et al. report the use of lead as an
lOCC. In U.S. Patent No. 5,543,547, Iwane et al. report the use of trivalent ceriimi as
an lOCC. In U.S. Patent No. 5,726,340, Takagi et al. report the use of lead and cobah
as a binary lOCC system. In Japanese Unexamined Patent Application No. 10-
316627, Yoneyama et al. report the use of manganese and the combination of
manganese and lead as lOCC's.
The literature is silent, however, as to the role of the lOCC in the carbonylation
reaction (i.e. the reaction mechanism). Accordingly, meaningful guidance regarding
the identification of additional lOCC systems is cursory at best. Periodic table
groupings have failed to provide guidance in identifying additional lOCC's. For
example, U.S. Patent No. 5,856,554 provides a general listing of possible lOCC
candidates, yet fixrther analysis has revealed that many of the members (and
combinations of members) of the recited groups (i.e.. Groups IV B and V B) do not
catalyze the carbonylation reaction. Therefore, due to the lack of guidance in the
literature, the identification of effective carbonylation catalyst systems has become a
serendipitous exercise.
As the demand for high performance plastics has continued to grow, new and
improved methods of providing product more economically are needed to supply the
market. In this context, various processes and catalyst systems are constantly being
evaluated; however, the identities of improved and/or additional effective catalyst
systems for these processes continue to elude the industry. Consequently, a long felt,
yet imsatisfied need exists for new and improved methods and catalyst systems for
producing aromatic carbonates and the like.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a method and catalyst system for
producing aromatic carbonates. In one embodiment, the present invention provides a
method of carbonylating aromatic hydroxy compounds by contacting at least one
aromatic hydroxy compound with oxygen and carbon monoxide in the presence of a
carbonylation catalyst system that includes a catalytic amoimt of an inorganic co-
catalyst containing titanium.
In various alternative embodiments, the carbonylation catalyst system can
include an effective amount of a palladium source and an effective amount of a halide
composition. Further alternative embodiments can include catalytic amounts of
various co-catalyst combinations, such as titanium and copper; titanium £ind nickel;
titanium and bismuth; titanium, bismuth, and manganese; titanium, manganese, and
europium; titanium, copper, and cerium; titanium, copper, and manganese; titanium,
copper, and europium; titanium and zinc; titanium and manganese; and titanium and
cerium.
BRIEF DESCRIPTION OF THE DRAWING
Various features, aspects, and advantages of the present invention will become
more apparent with reference to the following description, appended claims, and
accompanying drawing, wherein the FIGURE is a schematic view of a device capable
of performing an aspect of an embodiment of the present invention.
DETAILED DESCRIPTION
The present invention is directed to a method and catalyst system for producing
aromatic carbonates. In one embodiment, the method includes the step of contacting
at least one aromatic hydroxy compound with oxygen and carbon monoxide in the
presence of a carbonylation catalyst system that includes a catalytic amount of an
inorganic co-catalyst containing titanium. In alternative embodiments, the catalyst
system can include an effective amount of a Group VIII B metal and an effective
amount of a halide composition.
Unless otherwise noted, the term "effective amount," as used herein, includes that
amount of a substance capable of either increasing (directly or indirectly) the yield of
the carbonylation product or increasing selectivity toward an aromatic carbonate.
Optimum amoimts of a given reactant can vary based on reaction conditions and the
identity of other constituents yet can be readily determined in light of the discrete
circumstances of a given application.
Aromatic hydroxy compounds which may be used in the practice of the present
invention include aromatic mono or polyhydroxy compounds, such as phenol, cresol,
xylenol, resorcinol, hydroquinone, and bisphenol A. Aromatic organic mono hydroxy
compounds are preferred, with phenol being more preferred.
In various preferred embodiments, the carbonylation catalyst system can contain at
least one constituent from the Group VIII B metals or a compound thereof A
preferred Group VIII B constituent is an-effective amount of a palladium source. In
various embodiments, the palladium source may be in elemental form, or it may be
employed as a palladium compound. Accordingly, palladium black or elemental
palladium deposited on carbon may be used as well as palladium halides, nitrates,
carboxylates, oxides and palladium complexes containing carbon monoxide, amines,
phosphines or olefins. As used herein, the term "complexes" includes coordination or
complex compounds containing a central ion or atom. The complexes may be
nonionic, cationic, or anionic, depending on the charges carried by the central atom
and the coordinated groups. Other common names for these complexes include
complex ions (if electrically charged), Werner complexes, and coordination
complexes.
In various applications, it may be preferable to utilize palladium (II) salts of organic
acids, including carboxylates with C2_6 aliphatic acids. Palladimn(II) acetylacetonate
is also a suitable palladium source. Preferably, the amount of Group VIII B metal
source employed should be sufficient to provide about 1 mole of metal per 800-
10,000 moles of aromatic hydroxy compound. More preferably, the proportion of
Group VIII B metal source employed should be sufficient to provide about 1 mole of
metal per 2,000-5,000 moles of aromatic hydroxy compound.
The carbonylation catalyst system may further contain an effective amount of a halide
composition, such as an organic halide salt. In various preferred embodiments, the
halide composition can be an organic bromide salt. The salt may be a quaternary
ammonium or phosphonium salt, or a hexaalkylguanidinium bromide. In various
embodiments, a, a)-bis(pentaalkylguanidinium)alkane salts may be preferred. Suitable
organic halide compositions include tetrabutylammonium bromide,
tetraethylammonium bromide, and hexaethylguanidinium bromide. In preferred
embodiments, the carbonylation catalyst system can contain between about 5 and
about 1000 moles of bromide per mole of palladium employed, and, more preferably,
between about 50 and about 150 molar equivalents of bromide are used.
The formation of diaryl carbonates in a carbonylation reaction can be accompanied by
the formation of by-products, such as bisphenols, in varying proportions. In order to
increase selectivity to diaryl carbonate, various organic co-catalysts may be
incorporated in the carbonylation catalyst system. Depending on the application,
suitable organic co-catalyst may include various phosphine, quinone, terpyridine,
phenanthroline, quinoline and isoquinoline compounds and their derivatives, such as
2,2':6',2-terpyridine, 4'-methylthio-2,2':6',2-terpyridine, 2,2':6',2-terpyridine N-
oxide, 1,10-phenanthroline, 2,4,7,8-tetramethyl-l,I0-phenanthroline, 4,7-diphenyl-
1,10-phenanthroline and 3,4,7,8-tetramethyl-l,10-phenanthroline.
The carbonylation catalyst system includes a catalytic amount of an inorganic co-
catalyst (lOCC) containing titanium. In addition to titanium per se, it has been
discovered that certain lOCC combinations can effectively catalyze the carbonylation
reaction. Such lOCC combinations include titanium and copper; titanium and nickel;
titanium and bismuth; titanium, bismuth, and manganese; titanium, manganese, and
europiiun; titanium, copper, and cerium; titanium, copper, and manganese; titanium,
copper, and europium; titanium and zinc; titanium and manganese; and titanium and
cerium.
An lOCC can be introduced to the carbonylation reaction in various forms, including
salts and complexes, such as tetradentate, pentadentate, hexadentate, or octadentate
complexes. Illustrative forms may include oxides, halides, carboxylates, diketones
(including beta-diketones), nitrates, complexes containing carbon monoxide or
olefins, and the like. Suitable beta-diketones include those known in the art as ligands
for the lOCC metals of the present invention. Examples include, but are not limited
to, acetylacetone, benzoylacetone, dibenzoylmethane, diisobutyrylmethane, 2,2-
dimethylheptane-3,5-dione, 2,2,6-trimethylheptane-3,5-dione, dipivaloylmethane, and
tetramethylheptanedione. The quantity of ligand is preferably not such that it
interferes with the carbonylation reaction itself, with the isolation or purification of
the product mixture, or with the recovery and reuse of catalyst components (such as
palladium). An lOCC may be used in its elemental form if sufficient reactive surface
area can be provided. In embodiments employing supported palladium, it is noted
that the titanium-based lOCC provides a discrete, catalytic source of titanium in a
form favorable for such catalysis.
lOCC's are included in the carbonylation catalyst system in catalytic amounts. In this
context a "catalytic amount" is an amount of lOCC (or combination of lOCC's) that
increases the number of moles of aromatic carbonate produced per mole of Group
VIII B metal utilized; increases the number of moles of aromatic carbonate produced
per mole of halide utilized; or increases selectivity toward aromatic carbonate
production beyond that obtained in the absence of the lOCC (or combination of
lOCC's). Optimum amounts of an lOCC in a given application will depend on various
factors, such as the identity of reactants and reaction conditions. For example, when
palladium is included in the reaction, the molar ratio of each lOCC relative to
palladiimi at the initiation of the reaction is preferably between about 0.1 and about
100. Additional lOCC's may be used in the carbonylation catalyst system, provided
the additional lOCC does not deactivate (i.e. "poison") the original lOCC. Examples
of suitable additional lOCC's include cobalt, lead, and iron.
The carbonylation reaction can be carried out in a batch reactor or a
continuous reactor system. Due in part to the low solubility of carbon monoxide in
organic hydroxy compounds, such as phenol, it is preferable that the reactor vessel be
pressurized. In preferred embodiments, gas can be supplied to the reactor vessel in
proportions of between about 2 and about 50 mole percent oxygen, with the balance
being carbon monoxide. Additional gases may be present in amounts that do not
deleteriously affect the carbonylation reaction. The gases may be introduced
separately or as a mixture. A total pressure in the range of between about 10 and
about 250 atmospheres is preferred. Drying agents, typically molecular sieves, may be
present in the reaction vessel. Reaction temperatures in the range of between about
60° C and about 150° C are preferred. Gas sparging or mixing can be used to aid the
reaction.
In order that those skilled in the art will be better able to practice the present invention
reference is made to the FIGURE, which shows an example of a continuous reactor
system for producing aromatic carbonates. The symbol "V" indicates a valve and the
symbol "P" indicates a pressure gauge.
The system includes a carbon monoxide gas inlet 10, an oxygen inlet 11, a manifold
vent 12, and an inlet 13 for a gas, such as carbon dioxide. A reaction mixture can be
fed into a low pressure reservoir 20, or a high pressure reservoir 21, which can be
operated at a higher pressure than the reactor for the duration of the reaction. The
system further includes a reservoir outlet 22 and a reservoir inlet 23. The gas feed
pressure can be adjusted to a value greater than the desired reactor pressure with a
pressure regulator 30. The gas can be purified in a scrubber 31 and then fed into a
mass flow controller 32 to regulate flow rates. The reactor feed gas can be heated in a
heat exchanger 33 having appropriate conduit prior to being introduced to a reaction
vessel 40. The reaction vessel pressure can be controlled by a back pressure regulator
41. After passing through a condenser 25, the reactor gas effluent may be either
sampled for further analysis at valve 42 or vented to the atmosphere at valve 50. The
reactor liquid can be sampled at valve 43. An additional valve 44 can provide further
system control, but is typically closed during the gas flow reaction.
In the practice of one embodiment of the invention, the carbonylation catalyst system
and aromatic hydroxy compound are charged to the reactor system. The system is
sealed. Carbon monoxide and oxygen are introduced into an appropriate reservoir
until a preferred pressure (as previously defined) is achieved. Circulation of condenser
water is initiated, and the temperature of the heat exchanger 33 (e.g., oil bath) can be
raised to a desired operating temperature. A conduit 46 between heat exchanger 33
and reaction vessel 40 can be heated to maintain the desired operating temperature.
The pressiire in reaction vessel 40 can be controlled by the combination of reducing
pressure regulator 30 and back pressure regulator 41. Upon reaching the desired
reactor temperature, aliquots can be taken to monitor the reaction.
EXAMPLES
The following examples are included to provide additional guidance to those skilled
in the art in practicing the claimed invention. While some of the examples are
illustrative of various embodiments of the claimed invention, others are comparative
and are identified as such. The examples provided are merely representative of the
work that contributes to the teaching of the present application. Accordingly, these
examples are not intended to limit the invention, as defined in the appended claims, in
any maimer. Unless otherwise specified, all parts are by weight, and all equivalents
are relative to palladium. Reaction products were verified by gas chromatography. All
reactions were carried out in a glass batch reactor at 90-100° C in a 10% O2 in CO
atmosphere at an operating pressure of 95-102 atm. Reaction time was generally 2-3
hours.
As discussed supra, the economics of aromatic carbonate production is dependent on
the number of moles of aromatic carbonate produced per mole of Group VIII B metal
utilized. In the following examples, the aromatic carbonate produced is
diphenylcarbonate (DPC) and the Group VIII B metal utilized is palladium. For
convenience, the number of moles of DPC produced per mole of palladium utilized is
referred to as the palladium turnover number (Pd TON).
BASELINE EXAMPLE
In order to determine the comparative efficacy of various embodiments of the
present invention, baseline data were produced by adding, at ambient conditions, 0.25
mM palladium(II) acetylacetonate and various amounts of halide compositions to a
glass reaction vessel containing phenol. The reactants were heated to 100°C for 3
hours in a 10 % oxygen in carbon monoxide atmosphere. After the reaction, samples
were analyzed for DPC by gas chromatography producing the following results:
EXAMPLE 1
Diphenyl carbonate was produced by adding, at ambient conditions, palladiuni(II)
acetylacetonate, hexaethylguanidinium bromide ("HegBr"), and titanium(IV) oxide
acetylacetonate as an inorganic co-catalyst to a glass reaction vessel containing
phenol. The reactants were heated to 100°C for 3 hours in a 10 % oxygen in carbon
monoxide atmosphere. After the reaction, samples were analyzed for DPC by gas
chromatography. The following results were observed:
These results show that a Pd TON at least as high as 359 can be obtained utilizing
titanium as an lOCC. Consequently, it is evident that an lOCC containing titanium
can effectively catalyze the carbonylation reaction.
EXAMPLE 2
The general procedure of Example 1 was repeated with 18.6 ppm palladium(II)
acetylacetonate, 123 equivalents of bromide in the form of tetraethylammonium
bromide ("TEABr"), and the following lOCC combination: 10.11 equivalents of
titanium in the form of titanium(IV) oxide acetylacetonate and 9.2 equivalents of
copper in the form of copper(II) acetylacetonate. The Pd TON was found to be 2776,
thus showing that the lOCC combination of titanium and copper can effectively
catalyze the carbonylation reaction.
The reaction was repeated with 25.1 ppm palladium(II) acetylacetonate and
various concentrations of bromide and lOCC to provide the following results:
In the above experiments, high copper content and high titanium content were
arbitrarily defined as 14.0 equivalents. Low copper content and low titanium content
were arbitrarily defined as 5.6 equivalents. High bromide content was defined as 159
equivalents. Low bromide content was defined as 80 equivalents. Based on the results
of these experiments, it is evident that the combinations of low titanium content, high
bromide content, and high or low copper content may provide superior performance
under certain reaction conditions.
EXAMPLE 3
The general procedure of Examples 1 and 2 was repeated with 18.6 ppm palladium(II)
acetylacetonate, 123 equivalents of bromide in the form of tetraethylammonium
bromide, and the following lOCC combination: 10.11 equivalents of titanixmi in the
form of titanium(IV) oxide acetylacetonate and 11 equivalents of nickel in the form of
nickel(II) acetylacetonate. The Pd TON was found to be 613, thus showing that the
EXAMPLE 4
The general procedure of Examples 1-3 was repeated with 0.25 mM palladium(II)
acetylacetonate, 60 equivalents of bromide in the form of hexaethylguanidinium
bromide ("HegBr"), and the following lOCC combination: 14 equivalents of titanium
in the form of titanium(IV) oxide acetylacetonate and 14 equivalents of bismuth in the
form of bismuth(III) tetramethylheptanedionate. The Pd TON was found to be 613,
thus showing that the lOCC combination of titanium and bismuth can effectively
catalyze the carbonylation reaction.
The reaction was repeated with 25 ppm palladium(II) acetylacetonate and
various concentrations of bromide and lOCC to provide the following results:
These results show that a Pd TON at least as high as 1015 can be obtained utilizing
the lOCC combination of titanium and bismuth. Consequently, it is evident that this
lOCC combination can effectively catalyze the carbonylation reaction.
EXAMPLE 5
The general procedure of Examples 1-4 was repeated with 0.25 mM palladium(II)
acetylacetonate, 60 equivalents of bromide in the form of HegBr, and the following
lOCC combination: 14 equivalents of titanium in the form of titanium(IV) oxide
acetylacetonate, 14 equivalents of bismuth in the form of bismuth(III)
tetramethylheptanedionate, and 14 equivalents of manganese acetylacetonate. The Pd
TON was found to be 1421, thus showing that the lOCC combination of titanium,
bismuth, and manganese can effectively catalyze the carbonylation reaction.
The reaction was repeated with the same Ti, Bi, Mn lOCC combination (14
equivalents of each) and 25 ppm palladium(II) acetylacetonate. The reaction was
carried out in the absence of bromide. The Pd TON was foimd to be 184, thus
showing that the combination of titanium, bismuth and manganese can catalyze the
reaction without bromide.
EXAMPLE 6
The general procedure of Examples 1-5 was repeated with 0.25 mM palladium(II)
acetylacetonate, 60 equivalents of bromide in the form of HegBr, and the following
lOCC combination: 14 equivalents of titanium in the form of titanium(IV) oxide
acetylacetonate, 14 equivalents of manganese in the form of manganese(II)
acetylacetonate, and 14 equivalents of europium in the form of europium(III)
acetylacetonate. The Pd TON was found to be 791, thus showing that the lOCC
combination of titanium, manganese, and europium can effectively catalyze the
carbonylation reaction.
EXAMPLE 7
The general procedure of Examples 1-6 was repeated with 0.25 mM palladium(II)
acetylacetonate, 60 equivalents of bromide in the form of HegBr, and the following
lOCC combination: 14 equivalents of titanium in the form of titanium(IV) oxide
acetylacetonate, 14 equivalents of copper in the form of copper(n) acetylacetonate,
and 14 equivalents of cerium in the form of cerium(III) acetylacetonate. The Pd TON
was found to be 1278, thus showing that the lOCC combination of titanium, copper,
and cerium can effectively catalyze the carbonylation reaction.
EXAMPLES
The general procedure of Examples 1-7,was repeated with 0.25 mM palladium(II)
acetylacetonate, 60 equivalents of bromide in the form of HegBr, and the following
lOCC combination: 14 equivalents of titanium in the form of titanium(IV) oxide
acetylacetonate, 14 equivalents of copper in the form of copper(II) acetylacetonate,
and 14 equivalents of manganese in the form of manganese(II) acetylacetonate. The
Pd TON was found to be 620, thus showing that the lOCC combination of titanium,
copper, and manganese can effectively catalyze the carbonylation reaction.
The reaction was repeated with the same Ti, Cu, Mn lOCC combination (14
equivalents of each) and .25 mM palladium(II) acetylacetonate. The reaction was
carried out in the absence of bromide. The Pd TON was found to be 193, thus
showing that the combination of titanium, copper and manganese can catalyze the
reaction without bromide.
EXAMPLE 9
The general procedure of Examples 1-8 was repeated with 0.25 mM palladium(II)
acetylacetonate, 60 equivalents of bromide in the form of HegBr, and the following
lOCC combination: 14 equivalents of titanium in the form of titanium(IV) oxide
acetylacetonate, 14 equivalents of copper in the form of copper(II) acetylacetonate,
and 14 equivalents of europium in the form of europiiun(III) acetylacetonate. The Pd
TON was found to be 778, thus showing that the lOCC combination of titanium,
copper, and europium can effectively catalyze the carbonylation reaction.
EXAMPLE 10
The general procedure of Examples 1-9 was repeated with 18.6 ppm palladium(II)
acetylacetonate, 123 equivalents of bromide in the form of tetraethylanmionium
bromide, and the following lOCC combination: 10.11 equivalents of titanium in the
form of titanium(IV) oxide acetylacetonate and 11.14 equivalents of zinc in the form
of zinc(II) acetylacetonate. The Pd TON was found to be 2015, thus showing that the
lOCC combination of titanium and zinc can effectively catalyze the carbonylation
reaction.
The reaction was repeated with 25.1 ppm palladiiim(II) acetylacetonate and
various amounts of bromide and lOCC to provide the following results:
In the above experiments, high zinc content was arbitrarily defined as 14.1
equivalents, and high titanium content was arbitrarily defined as 14.0 equivalents.
Low zinc content and low titanium content were arbitrarily defined as 5.6 equivalents.
High bromide content was defined as 159 equivalents. Low bromide content was
defined as 80 equivalents. Based on the results of these experiments, it is evident that
the combination of high titanium content, high zinc content, and low bromide content
may provide superior performance under certain reaction conditions.
EXAMPLE 11
The general procedure of Examples 1-10 was repeated with 18.6 ppm palladiiuii(II)
acetylacetonate, 123 equivalents of bromide in the form of tetraethylammonium
bromide, and the following lOCC combination: 10.11 equivalents of titanium in the
form of titanium(IV) oxide acetylacetonate and 9.6 equivalents of manganese in the
form of manganese(II) acetylacetonate. The Pd TON was found to be 1618, thus
showing that the lOCC combination of titanium and manganese can effectively
catalyze the carbonylation reaction.
EXAMPLE 12
The general procedure of Examples 1-11 was repeated with 0.25 mM palladium(II)
acetylacetonate, 60 equivalents of bromide in the form of HegBr, and the following
lOCC combination: 14 equivalents of titanium in the form of titanium(IV) oxide
acetylacetonate and 14 equivalents of cerium in the form of cerium(III)
acetylacetonate. The Pd TON was found to be 616, thus showing that the lOCC
combination of titanium and cerium can effectively catalyze the carbonylation
reaction.
COMPARATIVE EXAMPLE A
It has been determined that several potential lOCC candidates do not catalyze
the carbonylation reaction and in fact may poison an otherwise effective lOCC
combination. For example, the general procedure of Examples 1-12 was repeated with
23 ppm palladium(II) acetylacetonate, 108 equivalents of bromide in the form of
tetraethylammonium bromide, and 9.8 'equivalents of tin in the form of tin(IV)
bisacetylacetonatedibromide as a potential lOCC candidate. The Pd TON was found
to be zero, thereby showing that Sn(IV) does not effectively catalyze the
carbonylation reaction at the conditions used.
COMPARATIVE EXAMPLE B
The general procedure of Examples 1-12 was repeated with 23 ppm palladium(II)
acetylacetonate, 108 equivalents of bromide in the form of tetraethylammonium
bromide, and the following lOCC combination: 10.0 equivalents of titanium in the
form of titanium(IV) oxide acetylacetonate and 9.8 equivalents of tin in the form of
tin(IV) bisacetylacetonatedibromide. The Pd TON was found to be zero, thereby
showing that, in addition to failing to effectively catalyze the carbonylation reaction
as a sole lOCC, Sn(IV) can poison an otherwise effective lOCC (i.e. titanium) at the
conditions used.
COMPARATIVE EXAMPLE C
The general procedure of Examples 1-12 was repeated with 23 ppm palladium(II)
acetylacetonate, 108 equivalents of bromide in the form of tetraethylammonium
bromide, and 9.8 equivalents of zirconium in the form of zirconium(IV)
acetylacetonate as a potential lOCC candidate. The Pd TON was found to be zero,
thereby showing that Zr(IV) does not effectively catalyze the carbonylation reaction
at the conditions used.
COMPARATIVE EXAMPLE D
The general procedure of Examples 1-12 was repeated with 23 ppm palladium(II)
acetylacetonate, 108 equivalents of bro;nide in the form of tetraethylammoniimi
bromide, and the following lOCC combination: 10.0 equivalents of titanium in the
form of titanium(IV) oxide acetylacetonate and 9.8 equivalents of zirconium in the
form of zirconium(IV) acetylacetonate. The Pd TON was found to be zero, thereby
showing that, in addition to failing to effectively catalyze the carbonylation reaction
as a sole lOCC, Zr(IV) can poison an otherwise effective lOCC (i.e. titanium) at the
conditions used.
It will be understood that each of the elements described above, or two or more
together, may also find utility in applications differing from the types described
herein. While the invention has been illustrated and described as embodied in a
method and catalyst system for producing aromatic carbonates, it is not intended to be
limited to the details shown, since various modifications and substitutions can be
made without departing in any way from the spirit of the present invention. For
example, additional effective lOCC compounds can be added to the reaction. As such,
further modifications and equivalents of the invention herein disclosed may occur to
persons skilled in the art using no more than routine experimentation, and all such
modifications and equivalents are believed to be within the spirit and scope of the
invention as defined by the following claims.
CLAIMS
What is claimed is:
1. A carbonylation catalyst system, comprising a catalytic amount of a
combination of inorganic co-catalysts comprising titanium and a substance selected
from the group consisting of copper; copper and cerium; copper and manganese;
copper and europium; nickel; bismuth; bismuth and manganese; zinc; manganese;
manganese and europium; and cerium.
2. The carbonylation catalyst system of claim 1, wherein the combination of
inorganic co-catalysts comprises titanium and copper.
3. The carbonylation catalyst system of claim 2, wherein the combination of
inorganic co-catalysts further comprises cerium.
4. The carbonylation catalyst system of claim 2, wherein the combination of
inorganic co-catalysts further comprises manganese.
5. The carbonylation catalyst system of claim 2, wherein the combination of
inorganic co-catalysts further comprises europium.
6. The carbonylation catalyst system of claim 1, wherein the combination of
inorganic co-catalysts comprises titanium and nickel.
21
7. The carbonylation catalyst system of claim 1, wherein the combination of
inorganic co-catalysts comprises titanium and bismuth.
8. The carbonylation catalyst system of claim 7, wherein the combination of
inorganic co-catalysts further comprises manganese.
9. The carbonylation catalyst system of claim 1, wherein the combination of
inorganic co-catalysts comprises titanium and zinc.
10. The carbonylation catalyst system of claim 1, wherein the combination of
inorganic co-catalysts comprises titanium and manganese.
11. The carbonylation catalyst system of claim 10, wherein the combination of
inorganic co-catalysts further comprises europium.
12. The carbonylation catalyst system of claim 1, wherein the combination of
inorganic co-catalysts comprises titanium and cerium.
13. The carbonylation catalyst system of claim 1, further comprising an effective
amount of a palladium source.
14. The carbonylation catalyst system of claim 13, wherein the palladium source
is a Pd(II) salt or complex.
15. The carbonylation catalyst system of claim 14, wherein the palladium source
is palladium acetylacetonate.
16. The carbonylation catalyst system of claim 13, wherein the palladium source
is supported Pd.
17. The carbonylation catalyst system of claim 16, wherein the palladium source
is palladium on carbon.
18. The carbonylation catalyst system of claim 13, further comprising an effective
amount of a halide composition.
19. The carbonylation catalyst system of claim 18, wherein the halide composition
is tetraethylammonium bromide.
20. The carbonylation catalyst system of claim 18, wherein the halide composition
is hexaethylguanidinium bromide.
21 The carbonylation catalysj system of claim 13, wherein the molar ratio of each
inorganic co-catalyst relative to palladium is between 0.1 and 100.
22. The carbonylation catalyst system of claim 1, wherein the titanium is initially
present as titaniuin(IV) oxide acetylacetonate.
23. A carbonylation catalyst system, consisting essentially of:
an effective amount of a palladium source;
an effective amount of a halide composition; and
a catalytic amount of an inorganic co-catalyst comprising titanium and a substance
selected from the group consisting of copper; copper and cerium; copper and
manganese; copper and europium; nickel; bismuth; bismuth and manganese; iinc;
manganese; manganese and europium; and cerium.
24. The carbonylation cataJyst system of claim 23, wherein the palladium source
is a Pd(II} salt or complex.
25. The carbonylation catalyst system of claim 24, wherein the palladium source
is palladium acetylacetonate.
26. The carbonylation catalyst system of claim 23, wherein the palladium source
is supported Pd.
27. The carbonylation catalyst system of claim 26, wherein the palladium source
is paliadium on carbon.
28. TTie carbonylation catalyst system of claim 23, wherein the halide composition
is tetraethylammonium bromide.
29. The carbonylation catalyst system of claim 23, wherein the halide composition
is hexaethylguanidinium bromide.
30. The carbonylation catalyst system of claim 23, wherein the molar ratio of
titanium relative to palladium is between 0.1 and 100.
31. The carbonylation catalyst system of claim 23, wherein the titanium is initially
present as titanium(IV) oxide acetylacetonate.
32. A method of carbonylating aromatic hydroxy compounds, said method
comprising the step of:
contacting at least one aromatic hydroxy compound with oxygen and carbon
monoxide in the presence of a carbonylation catalyst system comprising a catalytic
amount of a combination of inorganic co-catalysts comprising titanium and a
substance selected from the group consisting of copper; copper and cerium; copper
and manganese; copper and europium; nickel; bismuth; bismuth and manganese; zinc;
manganese; manganese and europium; and cerium.
33. The method of claim 32, wherein the combination of inorganic co-catalysts
comprises titanium and copper.
34. The method of claim 33, wherein the combination of inorganic co-catalysts
further comprises cerium.
35. The method of claim 33, wherein the combination of inorganic co-catalysts
further comprises manganese.
36. The method of claim 33, wherein the combination of inorganic co-catalysts
further comprises europium.
37. The method of claim 32, wherein the combination of inorganic co-catalysts
comprises titanium and nickel.
38. The method of claim 32, wherein the combination of inorganic co-catalysts
comprises titanium and bismuth.
39. The method of claim 38, wherein the combination of inorganic co-catalysts
further comprises manganese.
40. The method of claim 32, wherein the combination of inorganic co-catalysts
comprises titanium and zinc.
41. The method of claim 32, wherein the combination of inorganic co-catalysts
comprises titanium and manganese.
42. TTie method of claim 41, wherein the combination of inorganic co-catalysts
further comprises europium.
43. The method of claim 32, wherein the combination of inorganic co-catalysts
comprises titanium and cerium.
44. The method of claim 32, wherein the carbonylation catalyst system further
comprises an effective amount of a palladium source.
45. The method of claim 44, wherein the palladium source is a Pd(II) salt or
complex.
46. The method of claim 45, wherein the palladium source is palladium
acetyiacetonate.
47. The method of claim 44, wherein the palladium source is supported palladium.
48. The method of claim 47, wherein the supported palladium is palladium on
carbon.
49. The method of claim 44, wherein the carbonylation catalyst system further
comprises an effective amount of a halide composition.
50. The method of claim 49, wherein the halide composition is
tetraethylammonium bromide.
51. The method of claim 49, wherein the halide composition is
hexaethylguanidinium bromide.
52. The method of claim 32, wherein the aromatic hydroxy compound is phenol.
53. TTie method of claim 44, wherein the molar ratio of each inorganic co-catalyst
relative to palladium is between 0.1 and 100 at the initiation of the carbonylation.
54. The method of claim 32, wherein the titanium is initially supplied as
titanium(IV) oxide acetylacetonate.
55. A method of carbonylating aromatic hydroxy compounds, said method
comprising the step of
contacting at least one aromatic hydroxy compound with oxygen and carbon
monoxide in the presence of a carbonylation catalyst system consisting essentially of;
an effective amount of a palladium source;
an effective amount of a halide composition; and
a catalytic amount of an inorganic co-catalyst comprising titanium and a substance
selected from the group consisting of copper; copper and cerium; copper and
manganese; copper and europium; nickel; bismuth; bismuth and manganese; zinc;
manganese; manganese and europium; and cerium.
56. The method of claim 55, wherein the palladium source is a Pd(II) salt or
complex.
57. The method of claim 56, wherein the palladium source is palladium
acetylacetonate.
58. The method of claim 55, wherein the palladium source is supported palladiun).
59. The method of claim 58, wherein the supported palladium is palladium on
carbon.
60. The method of claim 55, wherein the halide composition is
tetraethylammonium bromide.
61. The method of claim 55, wherein the halide composition is
hexaethylguanidinium bromide,
62. The method of claim 55, wherein the aromatic hydroxy compound is phenol.
63. The method of claim 55, wherein the molar ratio of titanium relative to
palladium is between 0.1 and 100 at the initiation of the carbonylation.
64. The method of claim 55, wherein the titanium is initially supplied as
titanium(IV) oxide acetylacetonate.

A method and catalyst system for economically producing aromatic carbonates from
aromatic hydroxy compounds. In one embodiment, the present invention provides a
method of carbonylating aromatic hydroxy compounds by contacting at least one
aromatic hydroxy compound with oxygen and carbon monoxide in the presence of a
carbonylation catalyst system that includes a catalytic amount of an inorganic co-
catalyst containing titanium. In various alternative embodiments, the carbonylation
catalyst system can include an effective amount of a palladium source and an
effective amount of a halide composition. Further alternative embodiments can
include catalytic amounts of various inorganic co-catalyst combinations.