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ZA200303238B - Method for the production of form-selective catalysts and use thereof. - Google Patents

Method for the production of form-selective catalysts and use thereof. Download PDF

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Publication number
ZA200303238B
ZA200303238B ZA200303238A ZA200303238A ZA200303238B ZA 200303238 B ZA200303238 B ZA 200303238B ZA 200303238 A ZA200303238 A ZA 200303238A ZA 200303238 A ZA200303238 A ZA 200303238A ZA 200303238 B ZA200303238 B ZA 200303238B
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zeolite catalyst
zeolite
manufactured
metals
manufacturing
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ZA200303238A
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Mark Duda
Steffen Hasenzahl
Carsten Jost
Elias Klemm
Adolf Kuehnle
Andreas Reitzmann
Karsten Seelbach
Uwe Tanger
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Degussa
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    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D301/00Preparation of oxiranes
    • C07D301/02Synthesis of the oxirane ring
    • C07D301/03Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds
    • C07D301/12Synthesis of the oxirane ring by oxidation of unsaturated compounds, or of mixtures of unsaturated and saturated compounds with hydrogen peroxide or inorganic peroxides or peracids
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/74General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86Catalytic processes
    • B01D53/8621Removing nitrogen compounds
    • B01D53/8625Nitrogen oxides
    • B01D53/8628Processes characterised by a specific catalyst
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/74General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86Catalytic processes
    • B01D53/8668Removing organic compounds not provided for in B01D53/8603 - B01D53/8665
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J29/00Catalysts comprising molecular sieves
    • B01J29/04Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/061Crystalline aluminosilicate zeolites; Isomorphous compounds thereof containing metallic elements added to the zeolite
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C213/00Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C37/00Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
    • C07C37/60Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by oxidation reactions introducing directly hydroxy groups on a =CH-group belonging to a six-membered aromatic ring with the aid of other oxidants than molecular oxygen or their mixtures with molecular oxygen
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00Technologies relating to chemical industry
    • Y02P20/50Improvements relating to the production of bulk chemicals
    • Y02P20/52Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Biomedical Technology (AREA)
  • Health & Medical Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Catalysts (AREA)

Description

TT
0.2.5813 :
PROCESS FOR MANUFACTURING FORM-SELECTIVE
CATALYSTS AND THEIR USE
The present invention relates to a process for manufacturing form-selective catalysts on the basis of zeolites or mesoporous silicates by means of storing catalytically effective metal oxides as non-grid species in their channel and cavity structure, as well as the use of the catalysts thus produced.
In the past, zeolites have taken on more and more significance in the domain of catalyst research and in applied catalysis [Kerr, G.T. (1989): Spektrum der Wissenschaft 1989 (9), 94].
Compared to other catalysts zeolites offer countless advantages: 156 - They have a crystalline structure and accordingly a precisely defined configuration of
Si04- and AlO4 tetrahedrons. The result is good reproducibility in manufacture. - They have form selectivity, which means that only such molecules can be converted as are smaller than the pore diameter of the zeolites. - Targeted installation of acid centers in the intracrystalline surface is possible directly with synthesis and/or by subsequent ion exchange. - Above 300°C some zeolites have acid strengths in the mineral acid range. - Catalytically effective metal ions can be applied to the surface evenly through ion exchange or impregnation or can be incorporated into the crystal framework. Ensuing reduction to pure metal is possible. - Zeolite catalysts are thermostable up to at least 600°C, in some cases to higher temperatures, and can be regenerated by burning off carbon deposits.
Both zeolites and mesoporous silicates as well as their catalytic efficacy were described in detail by Sheldon et al. in Angew. Chem. 1997, 109, 1190-1211. So-called 'ship in a bottle’ complexes or 'zeozymes' are also explained. These are inclusions of metal complexes in large pores, so-called supercages. Oxidation-stable ligands, such as phthalocyanine, polypyridine
0.Z. 5813 and aromatic Schiff's bases are employed as metal complexes. Normal procedure is such that the complex is composed in the pores of the supercage by diffusing in the ligands. These phthalocyanines, polypyridines or aromatic Schiff's bases have a catalytic effect, but are sensitive at higher temperatures. To obtain the catalytic effect they may not be destroyed, thermally for example.
Zeolite catalysts, containing metals and/or metal oxides in the crystal lattice, are known. US
S756 861 and US § 672 777 accordingly describe a ZSM-5 zeolite for oxidation of benzenes.
EP 0889 018 likewise discloses a zeolite catalyst doped with Fe;O3. Minimal proportions of catalytically active iron additives in zeolites are described in US 5 110 995.
During synthesis of the zeolites foreign metals are usually added in the form of soluble salts, such as nitrates, and incorporated by hydrothermal crystallization at high temperatures into the crystal compound of the Si/Al lattice. An Si atom is substituted here, giving rise to a Bronsted acid center.
In general, when metal ions are incorporated into the crystal lattice so-called Bronsted acid centers are created, whereas when metal oxides are deposited, in the channel structure of the zeolites for example, so-called Lewis acid centers are created.
This acidic character can be determined by way of TPDA analyses, that is, temperature- programmed desorption of ammonia. A representation of this methodology is found in Berndt et al., Microporous Materials, s (1994) 197-204, Elsevier Science B.V., Amsterdam.
Foreign metal atoms, which are incorporated into the crystal compound during synthesis of zeolites, can leave these lattice sites when the catalyst mass is being calcined and be deposited into the cavities of the zeolite structure. The resulting metal centers exhibit high catalytic activity, for example with oxidation of benzenes to phenol derivatives (Panov et al., Appl.
Cat. A 141, 1996, 185-192 and Panov et al., Cat. Today 41, 1998, 365-385). This purely thermally induced exchange of foreign metals from lattice sites to metal centers deposited in
AMENDED SHEET
[a 3 cavities is thus a decisive step for the catalytic activity of the catalyst. Therefore, to improve the catalytic effect, as many metal centers as possible not localized to lattice sites of the : zeolites should be created.
A need exists to develop a zeolite catalyst which is thermally stable, contains catalytically effective metals, metal complexes and/or metal oxides in the manner of a 'ship in a bottle’ complex and which can be utilized for oxidation of organic substrates.
It was surprisingly found that the metals introduced by way of carbonyl, cyano and/or isonitrile complexes can be incorporated into the channel and cavity structure of a zeolite, that on the one hand a catalytic effect is obtained, but on the other hand little or no Bronsted acidity is generated, for example through incorporation of metal ions into the lattice framework.
It was also surprising that this absence of Bronsted acidity caused a drastic decline in the inclination to coking and associated loss in activity. In addition, it was surprising that metals, metal complexes and/or metal oxides can be included in a zeolite, such that these materials do not bleed out.
And it was also surprising that a large quantity of metal ions in the channel structure and thus high catalytic activity was present immediately following synthesis. As already mentioned, metal ions must be stimulated to migrate from lattice sites into the cavities of the zeolites usually through the calcination process.
Therefore a need exists for a process for manufacturing zeolite catalysts containing subgroup metals by hydrothermal synthesis with subsequent calcination, which is characterized in that the subgroup metals in the form of complexes of the general formula [metal,(CO).(CN)b(CNR)(X)g(Y)e]" withz>1,
R = alkyl chain with 1 to 10 carbon atoms,
0.Z. 5813 a, b, c, d and e = 0 or a whole number, whereby a, b, ¢, d and e can be identical or unidentical and the sum of a, b, c,d and e is > 1, n = 0 or is a negative or positive whole number and
X and Y represent a volatile component are introduced in the hydrothermal synthesis of the zeolite catalysts.
It is also an object of the invention to use the zeolite catalysts manufactured according to the present invention in processes for oxidation of organic substrates (for example benzene to phenol or generally for hydroxylation of aromatic compounds), as a denitrification catalyst (for example in automobile exhaust gas catalysts and in power plants) and in fuel cells.
Synthesis according to the present invention of the zeolite catalysts containing subgroup metals is carried out similarly to a hydrothermal method known per se for manufacturing zeolites, as described for example in US 4 410 501, US 3 702 886, US 5 055 623 or by Ione et al. in Usp. Khimii, 56 (3) 1987, 393 ff.
The process according to the present invention for manufacturing zeolite catalysts containing subgroup metals by hydrothermal synthesis with subsequent calcination is distinguished in that the subgroup metals in the form of complexes of the general formula [metal (CO)(CN),(CNR)(X)a(Y)e]™ >" @ withz > 1,
R = alkyl group with 1 to 10 carbon atoms, preferably a branched or unbranched alkyl chain with 1 to 10, quite particularly preferably with 1 to 3 carbon atoms, a, b, c,d and e = 0 or a whole number, whereby a, b, ¢, d and e can be identical or unidentical and the sum ofa, b,c,dand eis > 1, n = 0 or is a negative or positive whole number and
X and Y represent a volatile component, such as for example water or ammonia are introduced in the hydrothermal synthesis of the zeolite catalysts. The subgroup metals can thus be introduced as pure carbonyl, cyano and/or isonitrile complexes, as mixed complexes or carbonyl, cyano or isonitrile complexes mixed with other volatile ligands in the hydrothermal synthesis of the zeolite catalysts. Examples of such complexes are NH,
0z.5813 [Fe(CO)4(CN)], Fe(CO)4(CNR), Fe(CNR)4(CN),, where R can be an alkyl group, preferably a methyl or ethyl group.
The catalysts manufactured according to the present invention preferably exhibit pores having 5 a diameter of less than 15 Angstrom, particularly preferably a pore diameter of 4 to 7
Angstrom. A preferable structural form is constituted by zeolites of type MFI or ZSM-5, MEL or ZSM-11, though also ferrierite and beta.
The subgroup metals are introduced to the catalyst in the form of the complexes according to the present invention in accordance with formula I, thus for example in the form of cyano complexes, isonitrile complexes and/or carbonyl complexes by means of so-called template synthesis. After calcination, which preferably occurs at temperatures above 500°C, finely distributed metal oxide remains in the channel or cavity structure of the zeolites. This metal oxide can de reduced to the elementary metal by hydrogen as required. However, preferably the metal oxides resulting from the calcination process are used.
The complexes used according to the present invention in accordance with formula I should on the one hand be water-soluble, and on the other hand should remain stable in alkaline medium. Therefore the subgroup metals are preferably introduced to the hydrothermal synthesis of the zeolite catalysts in the form of the carbonyl or cyano complexes stable in an alkaline environment.
With cyanocomplexes a cation removable by calcination is preferred, and in particular an ammonium compound (NH,") is used here. Basically, all types of subgroup metal cyanocomplexes are suitable, preferably those with 6 coordination points, for example having an octahedral structure, with 4 coordination points, for example having a planar or tetrahedral structure, particularly preferably those based on metals such as vanadium, chromium, molybdenum, tungsten, manganese, titanium, zirconium, hafnium, technetium, rhenium, iron, ruthenium, osmium, copper, cobalt, rhodium, nickel, iridium, palladium, platinum, gallium, silver and/or gold, particularly preferable are ammoniumtetracyanonickelate, ammoniumtetracyanopalladate, ammoniumtetracyanoplatinate,
07.5813 ammoniumhexacyanoruthenate, ammoniumhexacyanoplatinate, ammoniumhexacyanocobaltate, ammoniumhexacyanochromate and ammoniumhexacyanoferrate. Likewise suitable are mixed complexes of these metals with the general structural formula [metal(CN)sX]™, whereby X represents a volatile component such as water or ammonia.
Amongst carbonyl compounds both mononuclear and polynuclear carbonyls of varying structure of the above-mentioned metals are suitable, in this case preferably iron pentacarbonyl. Likewise suitable are carbonyl metallic anions of the general structural formula
NHi[metal(CO)™], in this case particularly ammoniumtetracarbonylferrate.
Isonitrile complexes can also be added pure or as mixed complexes of the metals claimed according to the present invention in accordance with formula I.
If iron is used as a catalytically active subgroup metal, according to the present invention it can be added to the reaction mixture for example as ammoniumhexacyanoferrate. Iron can be present in both divalent and/or trivalent form. It is also possible to add other stable complexes, such as iron carbonyls for example that are soluble in hot water or in alkaline medium, for example iron pentacarbonyl.
Certain metals, which are less capable of forming acid centers, such as for example Ti present in the 4th subgroup of the periodic table, can of course be incorporated without a problem.
Conventional titanium silicalite, which for example according to US Patent 4 410 501 is manufactured from a hydrolysable titanium compound, such as TiCls, TiOCl,, tetraalkoxytitanium, preferably tetraethoxytitanium, as well as from tetraethylorthosilicate and tetrapropylammoniumhydroxide, can thus be modified with ammoniumhexacyanoferrate or iron carbonyls according to the present invention, by means of which it is likewise well suited to the applications according to the present invention.
The acidity of the catalysts can be altered by way of the calcination process or by subsequent hydrothermal treatment with a gas containing water vapor at a temperature between 300 and
0.Z. 5813 950°C, but also by incorporation of specific metals. With hydrothermal treatment with water vapor the zeolite catalyst is processed at a temperature of 300 to 950°C, preferably 450 to 800°C with a gas containing from 1 to 100 mole percent, preferably from 10 to 100 mole percent and quite particularly from 50 to 99 mole percent water vapor. Examples of such suitable procedures are disclosed in WO 95/27560 (1995) or in DE 196 34 406 (1996). Such treatment can further raise the Lewis acidity.
With the use of trivalent metals such as aluminum, for example triisobutylaluminum, a required acid strength of the catalyst can be adjusted precisely. If little or almost no presence of acid centers, in particular of Bronsted acid centers, is required, as for example in oxidation reactions, it is recommended that the molar ratio of SiO, : Al,O; present after calcination is no more than 1 : 102. The catalyst according to the present invention particularly preferably contains no aluminum,
Catalysts with a molar ratio of SiO; to the subgroup metal of 1: 10° to 1: 3 x 10 (relative to the calcinated catalyst) are preferably obtained by the process according to the present invention. It can be advantageous if the molar ratios are in narrower ranges, such as for example 1:10* to 1:5 x 102 or 1:10 to 1: 102. These ratios apply for SiO, to the subgroup metal or subgroup metal oxide. In the case of iron as a subgroup metal the molar ratio of SiO; to FeO; is preferably between 1 : 107 (minimum) to 1: 1.5 x 1072 (maximum), preferably between 1: 10* (minimum) to 1 : 107 (maximum), particularly preferably between 1:0.6 x 10” (minimum) to 1 : 0.9 x 10” (maximum).
In particular a tetraalkylorthosilicate, such as for example tetraethylorthosilicate, any other silicate in colloidal form or a silicate of an alkali salt can be used as a silicon component in the process according to the present invention. The organic base can be a tetraalkylammoniumhydroxide, such as for example tetrapropylammoniumhydroxide.
The manufacturing method of the basic framework of the catalysts is described in US Patent
0.Z. 5813
According to the present invention, the transition metal can be added to the reaction mixture as ammoniumhexacyanometallate or ammoniumtetracyanometallate. It is also possible to add other stable complexes, for example carbonyls soluble in hot water or in alkaline medium.
Unsuitable for this are all compounds which do not represent stable complexes — in particular in alkaline medium - such as for example transition metal citrates and transition metal acetylacetonates, because they are incorporated solidly into the lattice framework and — in particular if they are not quadrivalent — create strong acid centers.
If a surplus of ammoniumhexacyano or ammoniumtetracyanometallates or metal carbonyls is used, these are also separated on the surface of the zeolites as oxides, apart from being deposited on non-lattice sites. This is generally not a disadvantage. In individual cases an additional catalytic effect can even arise as a result of this.
Of course catalysts manufactured according to the present invention can also be used in membranes with pore diameters of less than 2000 Angstrém. With pore diameters of 50 to 1000 Angstrom special ultrafiltration membranes are utilized. If the catalysts are used in the manufacture of nanofiltration membranes, the pore diameter fluctuates between 5 and 50
Angstrom. With a pore diameter of approx. 5 Angstrém these membranes are also suitable for gas separation. In particular they can also be used in batteries or fuel cells in connection with membrane applications. Use of the zeolite catalyst containing subgroup metals is therefore thoroughly possible in fuel cells.
The catalysts manufactured according to the present invention can be used in a broad range of applications in industrial chemistry, such as isomerization reactions, hydrogenation reactions, dehydrogenation reactions, alkylation reactions, disproportionation reactions, formation of alcohol from olefins, epoxidation, coupling reactions, substitution reactions, cycloaddition and cycloreversion reactions, formation of ether, crude oil cracking, hydrocracking, Fischer-
Tropsch synthesis of alcohols or hydrocarbons, methanol synthesis from synthesis gas or methane, though in particular for oxidation reactions of organic substrates with atmospheric oxygen, hydrogen peroxide, organic peroxides or dinitrogen monoxide.
0.Z.5813
Use of the zeolite catalyst containing subgroup metals according to the present invention for oxidation of organic substrates is particularly preferred, in particular for manufacturing substituted and unsubstituted hydroxy aromatic compounds. The zeolite catalysts containing subgroup metals can be used in particular as a catalyst for manufacturing phenol from benzene, cresol from toluene, phenol substituted with several methyl groups from the corresponding benzene derivative, trimethylphenol and trimethylhydroquinone from trimethylbenzene, nitrophenol from nitrobenzene, phenol substituted with halogen from benzene substituted with halogen or aminophenol from aminobenzene.
Likewise the zeolite catalysts according to the present invention can be used as catalysts in the manufacture of multiple hydroxylated substituted and unsubstituted benzenes such as pyrocatechines, hydroquinones, pyrogallol and phloroglucine. Furthermore, with use of the zeolite catalysts according to the present invention multiple alkylsubstituted benzenes are hydroxylated. In this way trimethylbenzene for example can be oxidized to trimethylphenol or trimethylhydroquinone. In this way also tocopherols can be manufactured by use of the zeolite catalyst containing subgroup metals. This is an example of a route for synthesizing o- tocopherol (Vitamin E), with the result that the catalyst according to the present invention can be utilized as a catalyst in the production of a-tocopherol.
The production of propylene oxide, based on propene and hydrogen peroxide or dinitrogen monoxide is also preferred. This may occur in both the liquid phase and the gas phase. The zeolite catalyst according to the present invention can also be used for this process.
A further option for using the catalysts manufactured according to the present invention comprises a denitrification catalyst in power plants and in waste gas facilities of internal combustion engines, such as for example in vehicles or nitric acid plants for removing unwanted nitrogen oxides (NO).
These catalysts can also be used in fuel cells, in particular for coating the electrodes. In the latter case ammonium-hexacyanoplatinate can be used which can be reduced to atomic, finely
0.Z. 5813 distributed platinum after being deposited as oxide in the channel and cavity structure of a zeolite with hydrogen, for example.
Based on the example of oxidation of benzene to phenol on a catalyst manufactured according to the present invention, form selectivity and activity of the catalyst were examined on the one hand, and on the other hand a test was made via the use of dinitrogen monoxide as oxidation media as to how nitrogen oxides behave in this case.
Surprisingly, the synthesis of phenol from benzene was possible with a form-selective catalyst manufactured according to the present invention with high selectivity. The activity of the catalyst remained intact over the entire testing period. The dinitrogen monoxide was decomposed in pure nitrogen and oxidatively effective oxygen.
Use of the catalysts manufactured according to the present invention in processes for oxidizing organic substrates, for example of benzene or benzene derivatives, can be carried out, in which case a catalytic oxidation of the substrate with a gas containing dinitrogen monoxide at temperatures between 100 - 800°C, preferably 300 - 500°C is carried out. The process is particularly suitable for the manufacture of phenol from benzene.
Tubular reactors are usually used for this reaction. Larger experimental reactors have for example an inner diameter of 0.05 m and a length of approximately over 3.0 m. For tests on a laboratory scale, however, commercially available differential recycle reactors (see examples) are frequently utilized.
Various sources are considered for dinitrogen monoxide. The catalytic decomposition of ammonium nitrate at 100 - 160°C with manganese, copper, lead, bismuth, cobalt and nickel catalysts supplies a mixture of dinitrogen monoxide, nitrogen oxide and nitrogen dioxide, so that the gas cannot be used directly for oxidation of benzene.
Somewhat more favorable are the oxidation of ammonia with oxygen on platinum or bismuth oxide catalysts at 200 - 500°C, as well as the conversion of nitrogen oxide with carbon
0.Z. 5813 monoxide on platinum catalysts. In the first case water occurs as a by-product, in the second case carbon dioxide. The dinitrogen monoxide manufactured in this way can usually not be used directly for benzene oxidation. Likewise dinitrogen monoxide occurring during adipic acid manufacture cannot be used directly for oxidation, but must undergo a separate cleaning step. In particular, the oxygen contained in waste gas and the NOX interfere.
In recent times new processes have been developed for the production of dinitrogen monoxide, which are based in principle on ammonia and atmospheric oxygen, so that dinitrogen monoxide is produced cost-effectively. By way of example the direct manufacture of dinitrogen monoxide (N20) is explained comprehensively in Chem. Systems 98/99S14 (1999).
The gas containing dinitrogen monoxide can contain inert gases such as nitrogen and rare gases. But also ammonia and water vapor as well as traces of other nitrous oxides or air may be present.
Of course, microwave technology can also be applied in the manufacture of phenol and its derivatives based on benzene or the corresponding benzene derivatives for increasing selectivity and conversion. Phenol and its derivatives can be stimulated by microwaves for rotation and are thereby dissolved from the catalyst particularly easily.
Examples: 1. Manufacture of the catalysts, Variant 1 340 to 350 g of the respective starting mixture (see formulations) are stirred in a glass flask under exclusion of air with 615 g 25% tetrapropyl-ammonium-hydroxide solution in water for 1 hour. Next, this is heated carefully and evenly over the course of 5 hours to 90°C and the alcohol thus released is expelled. The volume is then supplemented with 1150 g distilled water and the homogeneous liquid is added to an autoclave fitted with an agitator. The mixture is heated to 175°C and left for a period of 10 days with constant stirring under its own pressure. It is then cooled and the solids are filtered off and washed
0O.Z. 5813 several times with hot distilled water. Then the product is completely dried, heated at a heating rate of 0.5°C/min and calcined for 6 hours at 550°C in the presence of atmospheric air.
The activity of the catalyst is determined via GC with reference to the measured conversion. The BET surface areas all lie between 400 and 600 m*/g, the average value of the pore size lies somewhere between 5 and 7 Angstrém, determined according to
Horvath and Kawazoe (J. Chem. Eng. Jpn. 16, 1983, 470 ff.). 1.1 Catalyst, not according to the present invention
Starting mixture:
Tetraethylorthosilicate 340.22 g
Iron (Ill)citrate, monohydrate 6.13 g
Average pore size: approx. 5.5 Angstr6m
BET surface area: 470 m*/g
Analysis of the end product (% by weight):
SiO, 98.12%
Fe,O3 1.86 % 1.2 Catalyst, not according to the present invention
Starting mixture:
Tetraethylorthosilicate 340.22 g
Iron (IlD)acetylacetonate 822¢
Average pore size: approx. 5.5 Angstrom
BET surface area: 480 m*/g
Analysis of the end product (% by weight):
SiO, 98.12 %

Claims (21)

AMENDED SHEET ho ® 23 Claims, amended:
1. A process for manufacturing zeolite catalysts containing subgroup metals by hydrothermal synthesis with subsequent calcination, wherein the subgroup metals in the form of complexes of the general formula [metal (CO)(CN)y(CNR)(X)a(Y)e]™ *™ withz > 1, R = alkyl chain with 1 to 10 carbon atoms, a, b, c,d and e = 0 or a whole number, wherein a, b, ¢, d and e€ can be identical or unidentical and the sum of a,b,c, dand eis > 1, n = 0 or is a negative or positive whole number and X and Y represent a volatile component, are introduced to the hydrothermal synthesis of the zeolite catalysts, whereby a cation removable by calcination is used in cyanocomplexes.
2. Process as claimed in Claim 1, wherein the subgroup metals are introduced to the hydrothermal synthesis of the zeolite catalysts in the form of pure or mixed carbonyl, cyano or isonitrile complexes.
3. Process as claimed in either of Claims 1 or 2, wherein the subgroup metals are introduced to the hydrothermal synthesis of the zeolite catalysts in the form of carbonyl or cyano complexes stable in an alkaline environment.
4. Process as claimed in any one of Claims 1 to 3, wherein vanadium, chromium, molybdenum, wolfram, manganese, titanium, zirconium, hafnium, technetium, rhenium, iron, ruthenium, osmium, copper, cobalt, rhodium, iridium, nickel, palladium, silver, gallium, gold and/or platinum is used as subgroup metal. AMENDED SHEET
AMENDED SHEET
5. Process as claimed in any one of Claims 1 to 4, wherein iron pentacarbonyl or ammoniumtetracarbonylferrate is used as carbonyl complex.
6. Process as claimed in any one of Claims 1 to 4, wherein ammoniumtetracyanonickelate, ammoniumtetracyanopalladate, ammoniumtetracyanoplatinate, ammoniumhexacyanoruthenate, ammoniumhexacyanoplatinate, ammoniumhexacyanocobaltate, ammoniumhexacyanochromate or ammoniumhexacyanoferrate is used as cyano complex.
7. Process as claimed in any one of Claims 1 to 6, wherein the molar ratio of SiO; to ALO; of the calcined zeolite catalyst is maximum 1 : 10.
8. Process as claimed in any one of Claims 1 to 7, wherein the molar ratio of SiO; to the subgroup metal of the calcined zeolite catalyst is between 1:10%to 1:3 x 1072 :
9. Process as claimed in any one of Claims 1 to 8, wherein the zeolite catalyst undergoes hydrothermal treatment with water vapor, whereby the zeolite catalyst is treated at a temperature between 300 to 950°C with a gas containing 1 to 100 mol% water vapor.
10. Use of the zeolite catalyst containing subgroup metals, manufactured as claimed in any one of Claims 1 to 9, for oxidizing organic substrates.
11. Use of the zeolite catalyst containing subgroup metals, manufactured as claimed in AMENDED SHEET
AMENDED SHEET any one of Claims 1 to 9, for manufacturing substituted and unsubstituted hydroxy aromatic compounds.
12. Use of the zeolite catalyst containing subgroup metals, manufactured as claimed in any one of Claims 1 to 9, for manufacturing phenol from benzene, cresol from toluene, phenol substituted with several methyl groups from the corresponding benzene derivative, trimethylphenol and trimethylhydroquinone from trimethylbenzene, nitrophenol from nitrobenzene, phenol substituted with halogen from benzene substituted with halogen or aminophenol from aminobenzene.
13. Use of the zeolite catalyst containing subgroup metals, manufactured as claimed in any one of Claims 1 to 9, for manufacturing pyrocatechin, resorcinol, hydroquinone, pyrogallol or phloroglucine.
14. Use of the zeolite catalyst containing subgroup metals, manufactured as claimed in any one of Claims 1 to 9, for manufacturing tocopherolene.
15. Use of the zeolite catalyst containing subgroup metals, manufactured as claimed in any one of Claims 1 to 9, for manufacturing propylene oxide from propene with hydrogen peroxide, or with dinitrogen monoxide.
16. Use of the zeolite catalyst containing subgroup metals, manufactured as claimed in any one of Claims 1 to 9, as catalyst for removing nitrogen.
17.Use of the zeolite catalyst containing subgroup metals, manufactured as claimed in any one of Claims 1 to 9, in fuel cells.
18. A process according to the invention for manufacturing zeolite catalysts, substantially as hereinbefore described and exemplified.
19. A process for manufacturing zeolite catalysts including any new and inventive integer or combination of integers, substantially as herein described. AMENDED SHEET
AMENDED SHEET
20.Use of the zeolite catalyst as claimed in any one of Claims 10 to 17, substantially as hereinbefore described and exemplified.
21.Use of the zeolite catalyst including any new and inventive integer or combination of integers, substantially as herein described.
ZA200303238A 2000-10-26 2003-04-25 Method for the production of form-selective catalysts and use thereof. ZA200303238B (en)

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