U.S. patent application number 14/294672 was filed with the patent office on 2014-09-18 for catalytically highly effective precious metal-carboxylate compounds of ir, ru, rh, pd and au.
This patent application is currently assigned to Heraeus Precious Metals GmbH & Co. KG. The applicant listed for this patent is Heraeus Precious Metals GmbH & Co. KG. Invention is credited to Horst Meyer, Jan Schapp, Steffen Voss, Richard Walter.
Application Number | 20140274670 14/294672 |
Document ID | / |
Family ID | 39535720 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140274670 |
Kind Code |
A1 |
Walter; Richard ; et
al. |
September 18, 2014 |
CATALYTICALLY HIGHLY EFFECTIVE PRECIOUS METAL-CARBOXYLATE COMPOUNDS
OF IR, RU, RH, PD AND AU
Abstract
The invention relates to a process for the production of noble
metal carboxylate compounds, in which a noble metal is digested
with at least one metal salt in a container and the digestion mass
is dissolved in a carboxylic acid and the metallic ions introduced
by the metal salt are separated from the resulting solution by
means of oxalate or an oxalate derivative.
Inventors: |
Walter; Richard; (Alzenau,
DE) ; Meyer; Horst; (Altenstadt, DE) ; Voss;
Steffen; (Los Alamitos, CA) ; Schapp; Jan;
(Long Beach, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Heraeus Precious Metals GmbH & Co. KG |
Hanau |
|
DE |
|
|
Assignee: |
Heraeus Precious Metals GmbH &
Co. KG
Hanau
DE
|
Family ID: |
39535720 |
Appl. No.: |
14/294672 |
Filed: |
June 3, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12531795 |
Nov 18, 2009 |
|
|
|
PCT/EP2008/002186 |
Mar 19, 2008 |
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14294672 |
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Current U.S.
Class: |
502/170 |
Current CPC
Class: |
C07C 51/412 20130101;
B01J 31/2239 20130101; C07C 51/412 20130101; B01J 2531/821
20130101; C07F 15/0053 20130101; B01J 31/04 20130101; B01J 2531/827
20130101; B01J 2231/34 20130101; C07C 55/07 20130101 |
Class at
Publication: |
502/170 |
International
Class: |
B01J 31/04 20060101
B01J031/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2007 |
DE |
10 2007 014 914.1 |
Claims
1-13. (canceled)
14. A process for the production of catalytically highly effective
noble metal carboxylate compounds or their solutions, wherein the
catalytically highly effective nobel metal carboxylate compounds or
their solutions comprise A) a noble metal carboxylate, wherein the
noble metal is selected from the group consisting of ruthenium,
platinum, palladium, rhodium and gold, and B) at least one compound
selected from the group consisting of oxalic acid. a salt of oxalic
acid, a derivative of oxalic acid and a salt of the derivative of
oxalic acid, said process comprising: digesting the noble metal
with alkaline earth peroxide; and dissolving a digestion mass in a
carboxylic acid or a carboxylic acid diluted with a protic solvent,
wherein, from a resulting solution, alkaline earth ions are
separated off as salt of an oxalic acid or salt of oxalic acid
derivatives.
15. The process according to claim 14, wherein the noble metal is
ruthenium or iridium.
16. The process according to claim 14, wherein the carboxylic acid
is acetic acid.
17. The process according to claim 14, wherein the noble metal
carboxylate is a noble metal acetate.
18. The process according to claim 14, wherein the alkaline earth
ions are selected from the group consisting of Calcium, Barium and
Strontium.
19. The process according to claim 14, wherein the protic solvent
is water or an alcohol.
Description
[0001] The invention relates to catalytically highly effective
noble metal carboxylate compounds of Ir, Ru, Rh, Pd, Pt and Au and
to processes for their production.
[0002] A known use of iridium, ruthenium and their compounds is
that as catalyst and catalyst precursor. Thus, according to EP 0
616 997 A1 and EP 0 786 447 A1, for example, iridium catalysts are
used in carbonylation reactions. Iridium acetate, among others, is
mentioned as iridium compound suitable for this purpose.
[0003] From the German patent application published for opposition
(Auslegeschrift) 1 127 888 it is known to produce vinyl esters of
higher carboxylic acids by reesterification of the vinyl esters of
lower carboxylic acids in the presence of platinum group metal
salts. Examples of suitable platinum group metal salts are, among
others, the acetates of palladium and rhodium obtained from the
hydroxides dissolved in glacial acetic acid by reaction with acetic
anhydride.
[0004] EP 0 844 251 relates to the production of ruthenium
carboxylate solutions from ruthenium(IV) oxide by reduction with
hydrazine derivative in the presence of a carboxylic acid. The
production of ruthenium oxide, in particular its filtration, is
highly time consuming.
[0005] In EP 1 046 629, a process for the production of Ir acetate
is described in which iridium hydroxide is precipitated from an
aqueous solution of an chloroiridium compound with an aqueous
solution of an alkali metal hydroxide, alkali metal carbonate or
alkali metal hydrogen carbonate, the precipitated iridium hydroxide
is separated off and reacted with acetic acid or a mixture of
acetic acid/acetic anhydride to form a solution containing iridium
acetate, and the iridium acetate is isolated from the solution as
solid.
[0006] Watson describes the production of Ir acetate (Precious
Metals Catalysts Seminar, page 83 ff.), in which Ir sponge is
sintered with barium peroxide. Subsequently, the sintered mass is
dissolved in a mixture of acetic acid/water and separated by
filtration from non-reacted metal. Barium sulphate is then
precipitated by the addition of sulphuric acid and separated from
the iridium acetate solution by filtration. Subsequently, the
iridium acetate solution is concentrated by evaporation. A key step
of this process is careful balancing during the removal of the
barium. Neither barium nor sulphates are desirable in the
end-product. For this reason, a highly accurate adjustment is
required in order to obtain the desired product.
[0007] This process has several disadvantages:
[0008] Accurately adjusting the sulphuric acid content is difficult
to carry out and needs to be verified analytically. For this
reason, repeated precipitation and filtration of barium sulphate
together with the corresponding analytical investigations are
necessary as a rule. A further disadvantage is the extremely
difficult and cost-intensive filtration of the Ba sulphate. In
addition, the concentration of the strontium contained therein
cannot be sufficiently reduced by this precipitation route and
consequently limits the purity of the product.
[0009] It is the object of the invention to provide catalytically
highly effective noble metal carboxylate compounds of Ir, Ru, Rh,
Pd, Pt and Au and a simple process for their production. The noble
metal carboxylate compounds produced according to the process, in
particular the acetate compounds, should be catalytically as highly
effective as possible. Preferably, the compounds should also have a
high purity and, in particular, have a low chlorine, sulphur,
sodium and potassium content.
[0010] To achieve this object, a melt or fusion mass exhibiting
noble metal and alkaline earth peroxide is dissolved in a
carboxylic acid, if necessary with an addition of water, and
subsequently filtered. From the filtered solution, the alkaline
earth ions introduced by the alkaline earth peroxide are separated
as salt of oxalic acid or salt of oxalic acid derivatives. Oxalate
derivatives in the case of which an organic radical is arranged
between the carboxyl groups have the same effect as oxalates. This
process is highly efficient and circumvents time consuming
BaSO.sub.4 precipitation and the filtration of barium sulphate
according to the Watson process. The purified noble metal
carboxylate solution can be concentrated, it being possible to
adjust the concentration increase to a desired concentration or to
carry it out up to the isolation of the solid.
[0011] For this purpose, the methods corresponding to the state of
the art such as evaporation of the reaction solution, spray drying
or precipitation at a low temperature or addition of a suitable
solvent are used. Surprisingly enough, the catalytic properties are
particularly good when a noble metal carboxylate solution, in
particular an acetic acid solution of ruthenium acetate or iridium
acetate originates from the process using the precipitation of the
alkaline earth metal as salt of oxalic acid or salt of oxalic acid
derivatives. In a solution thus produced, the mass of oxalic acid
and/or salts of oxalic acids or corresponding derivatives is
smaller or equal to the mass of noble metal.
[0012] Preferably, the noble metals are digested with calcium
peroxide or barium peroxide. Ruthenium and iridium are preferred
noble metals. Acetate is the preferred carboxylate. The digested
noble metal mixture dissolved in aqueous acetic acid is
correspondingly preferred. According to the invention, the
proportion of alkaline earth metal, in particular calcium,
strontium or barium, amounts to 100 ppm to 10% by weight, in
particular 500 ppm to 0.5% by weight, based on the noble metal,
following precipitation as salt of oxalic acid or salt of oxalic
acid derivatives. The calcium, strontium and barium content can be
considerably reduced by fractional crystallisation.
EXAMPLE 1
[0013] 1.5 g of ruthenium powder (14.8 mmole) and 10 g of barium
peroxide (purity 95.8%; 56.5 mmole) are mixed.
[0014] The mixture is transferred into a nickel crucible and heated
for 15 hours at 850.degree. C.
[0015] 150 ml of a mixture of acetic acid and water in a ratio of
2:1 are heated to 50.degree. C. in a 200 ml three-necked flask.
[0016] The reaction mixture of ruthenium powder and barium peroxide
is introduced into the three-necked flask. The mixture heats up to
80.degree. C. by exothermic reaction. The mixture is heated to
boiling temperature and stirred at boiling temperature for 3
hours.
[0017] Subsequently, the solution is cooled to room temperature and
filtered through a membrane filter. The filter cake is washed with
a little acetic acid/water mixture (2:1).
[0018] 169 g of solution with an Ru content of 0.88% (1.487 g Ru,
14.7 mmole) and a Ba content of 4.59% (7.757 g Ba, 56.5 mmole) are
obtained.
[0019] 169 g of Ru acetate solution (1.487 g Ru, 14.7 mmole) are
transferred into a 200 ml three-necked flask and 14.264 g of oxalic
acid dihydrate (113 mmole) are added with stirring. After an
agitation time of 4 hours the suspension is filtered on a black
band filter and subsequently on a membrane filter. The filter cake
is washed with acetic acid/water mixture (2:1). [0020] 230 g of
solution with a Ru content of 0.57% (1.311 g Ru, 13 mmole) and a Ba
content of 0.051% (0.117 g, 0.85 mmole) are obtained. The oxalate
content (content determination by ion chromatography) is 0.36%.
EXAMPLE 2
[0021] 1.5 g of ruthenium powder (14.8 mmole) and 10 g of barium
peroxide (purity 95.8%; 56.5 mmole) are mixed.
[0022] The mixture is transferred into a nickel crucible and heated
for 15 hours at 850.degree. C.
[0023] 150 ml of a mixture of acetic acid and water in a ratio of
2:1 are heated to 50.degree. C. in a 200 ml three-necked flask.
[0024] The reaction mixture of ruthenium powder and barium peroxide
is introduced into the three-necked flask. The mixture heats up to
76.degree. C. by exothermic reaction. The mixture is heated to
boiling temperature and stirred at boiling temperature for 3 hours.
Subsequently, the solution is cooled to room temperature and
filtered through a membrane filter. The filter cake is washed with
a little acetic acid.
[0025] 166 g of solution with an Ru content of 0.90% (1.494 g Ru,
14.8 mmole) and a Ba content of 4.67 (7.752 g Ba, 56.4 mmole) are
obtained.
[0026] 169 g of Ru acetate solution (1.494 g Ru, 14.8 mmole) are
transferred into a 200m1 three-necked flask and 14.264 g of oxalic
acid dihydrate (113 mmole) are added with stirring. After an
agitation time of 4 hours the suspension is filtered on a black
band filter and subsequently on a membrane filter. The filter cake
is washed with acetic acid. [0027] 193 g of solution with a Ru
content of 0.68% (1.314 g Ru, 13 mmole) and a Ba content of 0.0515%
(0.1 g, 0.72 mmole) are obtained. The oxalate content (content
determination by ion chromatography) is 0.26%.
EXAMPLE 3
[0028] 5.001 g of rhodium powder and 34.622 g of barium peroxide
were weighed into a glass with a screw cover and thoroughly mixed
for 10 minutes. The mixture was transferred into a nickel crucible
and subsequently heated at 850.degree. C. for 15 hours in a muffle
kiln. Subsequently, the crucible was cooled to room temperature.
The melt is black at its surface, homogenous and grey underneath.
The melt was introduced into a solution of acetic acid and fully
demineralised water and stirred, while the ratio of acetic acid to
water was 2:1 parts by volume. During this process, the temperature
rose to 24.degree. C. A dark green liquid with black particles was
obtained. After further stirring for 15 minutes, the mixture was
heated to 58.degree. C. and kept at this temperature for 5 hours.
During this process, the suspension adopted a brown colour within
approximately 5 minutes. Subsequently, the barium was precipitated
as salt with 51.453 grams of oxalic acid dehydrate and stirred for
a further hour whereupon a yellow liquid was filtered off via a
suction filter using a blue band filter. The filtrate was
concentrated in a rotation evaporator at a temperature of
75.degree. C. The rhodium acetate was dried up to mass constancy
and ground using a mortar. The dried yield of rhodium acetate was
11.012 g. The rhodium content was determined by ICP analysis as
being 34.43% by weight.
EXAMPLE 4
[0029] Iridium is digested with barium peroxide according to the
Watson process and dissolved with acetic acid. The barium from the
Watson process is precipitated with oxalic acid in a manner
analogous to the above example 1 to 3 and filtered off. Such
iridium carboxyl compounds, in particular acetates, exhibit
unrivalled catalytic properties.
* * * * *