WO2018088436A1

WO2018088436A1 - Ammoxmation catalyst and process for producing oxime

Info

Publication number: WO2018088436A1
Application number: PCT/JP2017/040295
Authority: WO
Inventors: Kenji UEURA; Yukimasa Fukuta; Yasushi Yamamoto; Richard Lewis; Simon FREAKLEY; Jennifer Edwards; Graham HUTCHINGS
Original assignee: Ube Industries, Ltd.; University College Cardiff Consultants Ltd
Priority date: 2016-11-11
Filing date: 2017-11-08
Publication date: 2018-05-17
Also published as: JP2020506789A; CN109789393A

Abstract

Disclosed is an ammoximation catalyst useful in producing oximes from ketones with high yield and high selectivity by ammoximation reaction using hydrogen, oxygen and ammonia. The ammoximation catalyst contains (a) a titanosilicate and (b) a metal supported on the titanosilicate and/or another support that is different from the titanosilicate; the metal comprising palladium and gold.

Description

AMMOXMATION CATALYST AND PROCESS FOR PRODUCING OXIME

The present invention relates to a catalyst for producing oximes useful as starting materials of amides or lactams, and a process for producing oximes. More specifically, the present invention relates to a catalyst and a process for producing oximes by ammoximation reaction of ketones.

As a process of producing oximes, there has been known a method of subjecting ketones to an ammoximation reaction with hydrogen peroxide and ammonia in the presence of titanosilicate as a catalyst, see, for example, Patent Document 1. This method is advantageous in that there is no need of neutralizing sulfuric acid with ammonia, not like a conventional process of oximation using hydroxylamine sulfate, and also advantageous in that the separation of the product and catalyst is easy due to a solid catalyst reaction.

Hydrogen peroxide used herein is produced by an organic method, an anthraquinone method, an electrolytic method or the like, in particular by an anthraquinone method as an industrial production method. However, the anthraquinone method has a problem of high capital investment costs because it includes multiple steps such as reduction and oxidation of anthraquinone media, extraction of hydrogen peroxide produced, purification, concentration and the like. In addition, it has additionally environmental problems such as large energy consumption, release of organic solvents into the atmosphere and the like. To solve these problems, methods other than the above method have been attempted. For example, a method of producing hydrogen peroxide directly from oxygen and hydrogen in a reaction medium in the presence of a catalyst is known.

In recent years, there have been proposed methods including forming hydrogen peroxide directly from hydrogen and oxygen in the presence of a catalyst and, without separating and purifying the hydrogen peroxide, performing ammoximation reaction of ketones with ammonia, wherein the catalyst is obtained by depositing a precious metal on titanosilicate as a support, see Patent Documents 2 to 4.

JP S62-59256 A (Patent Document 1) CN 101314577 A (Patent Document 2) CN 103288678 A (Patent Document 3) CN 103288679 A (Patent Document 4)

However, the methods disclosed in the above Patent Documents 2 to 4 using hydrogen and oxygen exhibit low conversion ratio of ketone and low hydrogen-basis selectivity. Therefore, they are not economically satisfactory and further improvement in yield of oxime is demanded.

The present invention was made to solve these problems and the purpose thereof is to provide a method of producing oximes with high yield and high selectivity.

The present inventors made an intensive investigation to solve the above problems. As a result, they have found that a catalyst containing a titanosilicate and palladium and gold supported on the titanosilicate and/or another support that is different from the titanosilicate produces oximes with high yield and high selectivity. In addition, they have found that the addition of an appropriate amount of carbon dioxide in ammoximation reaction in the presence of a catalyst produces oximes with high yield and high selectivity.

The present invention relates the following items.
1. An ammoximation catalyst for producing an oxime from a ketone by ammoximation reaction using hydrogen, oxygen and ammonia, the catalyst comprising:
(a) a titanosilicate and
(b) a metal supported on the titanosilicate and/or another support that is different from the titanosilicate; the metal comprising palladium and gold.

2. The ammoximation catalyst according to the above item 1, wherein a supporting amount of the metal is 0.01 to 20% by weight.

3. The ammoximation catalyst according to the above item 1 or 2, wherein a weight ratio of gold/palladium is 0.02 to 50.

4. The ammoximation catalyst according to any one of the above items 1 to 3, wherein a weight ratio of gold/palladium is 0.05 to 5.

5. The ammoximation catalyst according to any one of the above items 1 to 4, wherein the metal further comprises at least one metal selected from the group consisting of platinum, ruthenium, rhodium, osmium, iridium, silver, rhenium, tin, cobalt, nickel, copper and manganese.

6. The ammoximation catalyst according to any one of the above items 1 to 5, wherein the titanosilicate comprises TS-1.

7. The ammoximation catalyst according to any one of the above items 1 to 6, wherein the support for the metal is selected from the group consisting of titanium oxide, activated carbon, silica, alumina and iron oxide.

8. A process for producing an oxime from a ketone by ammoximation reaction using hydrogen, oxygen and ammonia in a presence of an ammoximation catalyst, the process comprising the step of:
performing the ammoximation reaction by supplying carbon dioxide in an amount of more than 0 and less than 10 times by mole based on an amount of ammonia.

9. The process according to the above item 8, wherein carbon dioxide is supplied in an amount of 0.1 times by mole or more and less than 10 times by mole, based on an amount of ammonia.

10. The process according to the above item 8 or 9, wherein carbon dioxide is supplied in an amount of 0.5 to 5 times by mole, based on an amount of ammonia.

11. The process according to any one of the above items 8 to 10, wherein a form of ammonia supplied to the reaction is selected from aqueous ammonia solution, gaseous ammonia, ammonium salts, and combination of two or more of these.

12. The process according to the above item 11, wherein at least a part of ammonia supplied to the reaction is in a form of ammonium salt, and the ammonium salt is at least one of ammonium carbonate and ammonium hydrogen carbonate.

13. The process according to any one of the above items 8 to 12, wherein a form of carbon dioxide supplied to the reaction is selected from carbon dioxide gas, carbonate salts, and combination of two or more of these.

14. The process according to the above item 13, wherein at least a part of carbon dioxide supplied to the reaction is in a form of carbonate salt, and the carbonate salt is at least one of ammonium carbonate and ammonium hydrogen carbonate.

15. The process according to any one of the above items 8 to 14, wherein the ammoximation catalyst comprises:
(a) a titanosilicate and
(b) a metal supported on the titanosilicate and/or another support that is different from the titanosilicate.

16. The process according to the above item 15, wherein the metal comprises palladium or a combination of palladium and one or more metals selected from the group consisting of gold, platinum, nickel, tin, rhenium, osmium, copper, iridium, ruthenium, rhodium, silver, cobalt and manganese.

According to the present invention, oximes are produced by ammoximation reaction, without supplying hydrogen peroxide, from ketones with high yield and high selectivity.

A catalyst of the present invention comprises (a) a titanosilicate and (b) a metal supported on the titanosilicate and/or another support that is different from the titanosilicate, wherein the metal comprises palladium and gold.

The titanosilicate used herein is a zeolite having titanium, silicon and oxygen as elements constituting a backbone, and may be those in which the backbone thereof may substantially constituted of titanium, silicon and oxygen, or may be those in which another element such as boron, aluminum, gallium, iron, chromium, and the like is contained as an element constituting a backbone.
The titanosilicate catalyst is not particularly limited as long as it is a porous titanosilicate in which a part of Si is replaced with Ti, and the examples thereof include crystalline titanosilicates, layered titanosilicates, and mesoporous titanosilicates. Examples of the crystalline titanosilicates include, when expressed by a Framework Type Code given by IZA (The International Zeolite Association), TS-2 having Framework Type MEL, Ti-ZSM-12 having Framework Type MTW (see, Zeolites 15, 236-242 (1995)), Ti-Beta having Framework Type BEA (see, Journal of Catalysis 199, 41-47 (2001)), Ti-MWW having Framework Type MWW (see, Chemistry. Letters. 774-775 (2000)), Ti-UTD-1 having Framework Type DON (see, Zeolites 15, 519-525 (1995)), and TS-1 having Framework Type MFI (see, Journal of Catalysis, 130, (1991), 1-8). Examples of the layered titanosilicates include Ti-MWW precursor (see, JP 2003-327425 A), Ti-YNU(see Angewante Chemie International Edition 43, 236-240 (2004)) and the like. Examples of the mesoporous titanosilicates include Ti-MCM-41 (see, Microporous Material 10, 259-271 (1997)), Ti-MCM-48 (see, Chemical Comunications 145-146 (1996)), Ti-SBA-15 (see, Chemistry of Materials 14, 1657-1664 (2002)), Ti-MMM-1 (see, Microporous and Mesoporou Materials 52, 11-18 (2002)), and the like.

Among these, preference is given to titanosilicates having structure of Framework Type MFI and Framework Type MWW. For example, those known as TS-1 zeolite which can be prepared by a method disclosed in JP S56-96720 A may be used. Titanosilicates having a silicon/titanium atomic ratio of 10 to 1000 are preferably used.

The metal may be supported on the above titanosilicate or supported on another support that is different from the titanosilicate. Examples of the support for supporting the metal include oxides such as silica, alumina, titania (titanium oxide), zirconia and niobia; hydrate compounds (hydrate form of oxides) such as niobic acid, zirconic acid, tungstic acid and titanic acid; carbons such as activated carbon, carbon black, graphite and carbon nanotubes; and titanosilicate and other zeolites. As a preferred support other than titanosilicate, titanium oxide, activated carbon, silica, alumina and iron oxide may be exemplified.

In the present invention, the titanosilicate is an essential component. If the metals are supported on a support that is different from the titanosilicate, titanosilicate is necessary to be included in addition to the support of the metal. Thus, with regard to the metal, (i) all of the metal may be supported on the above titanosilicate, (ii) a part of the metal may be supported on the titanosilicate, and (iii) all of the metal may be supported on the support that is different from the titanosilicate. Furthermore, the titanosilicate supporting the metal and the titanosilicate that are not supporting the metal may be present simultaneously.

From the view point of chemical engineering, it is advantageous to use one type of catalyst by giving multiple functions to a catalyst, rather than adding two or more type of catalysts having different specific gravities in a reactor, in order to achieve more uniform distribution of catalysts in the reactor. Therefore, it is preferred that the metals are supported on the titanosilicate.

In the catalyst of the present invention, at least palladium and gold are supported on the support, and in addition the catalyst may comprise one or more metals other than palladium and gold. The metals other than palladium and gold include platinum, ruthenium, rhodium, osmium, iridium, rhenium, silver, tin, cobalt, nickel, copper and manganese.

Supporting of the metals may be carried by impregnating a support with a solution or a colloidal solution of the metals, and drying, calcining or carrying out reduction treatment with a reducing agent. In the case of palladium and gold, supporting may be accomplished by impregnating a support with a solution of palladium salt and gold salt, or by impregnating a support with a colloidal solution containing palladium and gold. After the support is mixed with the aqueous solution of palladium salt and gold salt or palladium colloid and gold colloid to allow palladium and gold to be supported, generally water may be removed by filtration or condensation to produce a palladium and gold-supported catalyst.

Examples of palladium salt include, for example, palladium chloride, palladium nitrate, palladium sulfate, palladium acetate, tetraammine palladium chloride and the like. Examples of gold salt include, for example, gold chloride, chloroauric acid, gold acetate and the like. Solutions of palladium colloid and gold colloid are not particularly limited as long as palladium particles and gold particles are dispersed in a liquid. Generally, aqueous solutions are used. The concentration of palladium colloid and gold colloid are not particularly limited. Aqueous solutions of palladium and gold colloid can be used directly as the catalyst without any support, but it is preferred that the metals are supported from the view point of separation and purification.

Generally, after the supporting step, the catalyst is calcined in ambient atmosphere or in inert gas, or reduced with a reducing agent in liquid phase or gas phase, thereby producing a catalyst for use. The supporting amount of the metal is generally in the range of 0.01 to 20% by weight, preferably 0.1 to 5% by weight based on the weight of the support. Weight ratio of Au/Pd is preferably 0.02 to 50, and more preferably 0.05 to 5.

In case that the metals are supported on the titanosilicate, the metals are supported in the above-mentioned amount on the titanosilicate. In case that the metals are supported on another support that is different from the titanosilicate, titanosilicate needs to be present separately in an amount generally 5 to 10000 times by weight, for example 5 to 1000 times by weight, and preferably 20 to 1000 times by weight, based on the weight of the metals. In case that a part of the metals are supported on another support that is different from the titanosilicate, the total amount of titanosilicate (including support and non-support of the metals) is generally 5 to 10000 times by weight, for example 5 to 1000 times by weight, and preferably 20 to 1000 times by weight, based on the weight of the metals.

Other metals can be supported on supports by the same method. In case that one or more of the other metals are also supported, they are used, for example, in an amount of 0.01 to 10 times by weight based on the total amount of palladium and gold.

<Ammoximation reaction; production of oximes>
Next, the ammoximation reaction will be described. In the ammoximation reaction, ketones react to produce corresponding oximes in a presence of an ammoximation catalyst (e.g. the ammoximation catalyst of the present invention mentioned above) by using hydrogen (hydrogen source), oxygen (oxygen source) and ammonia (ammonia source).

Ketones used as a starting material in the ammoximation reaction may be any of aliphatic ketones, alicyclic ketones, and aromatic ketones, or a combination of two or more of these if needed. Examples of ketones include, for example, dialkyl ketone such as acetone, ethyl methyl ketone, isobutyl methyl ketone; alkyl alkenyl ketones such as mesityl oxide; alkyl aryl ketones such as acetophenone; diaryl ketones such as benzophenone; cycloalkanones such as cyclopentanone, cyclohexanone, cyclooctanone, and cyclododecanone; cycloalkenones such as cyclopentenone, and cyclohexenone and the like. Among these, cycloalkanones are most preferred.

The above ketones may be those obtained by oxidation of alkanes, oxidation (dehydrogenation) of secondary alcohols, or hydration and oxidation (dehydrogenation) of alkenes.

The use amount of an ammoximation catalyst to ketones can be varied widely depending on the forms of reaction. For example, in the case of batch reaction, a catalyst may be used in an amount of 0.01 to 200 parts by weight, preferably 0.1 to 100 parts by weight based on 100 parts by weight of ketones. In the case of continuous reaction, starting materials may be supplied such an amount that the space velocity of ketones are in the range about 0.01 to 1000 kg/h per 1kg of catalyst. In addition, in case that a continuous vessel type reactor is used, a catalyst may be used as a dispersion in a reaction mixture in such an amount that the content thereof is about 0.1 to about 20% by weight based on a liquid phase of the reaction mixture. In this case, source materials, solvent and gasses are continuously supplied to the reaction mixture in the reactor in which the catalyst is dispersed, and the liquid phase of the reaction mixture is continuously taken out of the reactor via a filer or the like to obtain a product.

Ammonia used in the ammoximation reaction may be supplied in various forms. As forms of ammonia (i.e. source of ammonia) supplied to the reaction, gaseous ammonia, liquid ammonia, and ammonia solution in which ammonia is dissolved in water or an organic solvent are exemplified. In addition, ammonium salts may be used as a source of ammonia. Examples of ammonium salts include ammonium carbonate, ammonium hydrogen carbonate, ammonium acetate, ammonium chloride and the like. Preference is given to ammonium carbonate, and ammonium hydrogen carbonate. Herein, one mole of ammonium carbonate is counted as two moles of ammonia, and one mole of ammonium hydrogen carbonate is counted as one mole of ammonia. The amount of ammonia used in the reaction is preferably one mole or more, more preferably one and half mole or more, based on one mole of ketone.
The upper limit of ammonia is not particularly restricted, and may be determined considering the easiness of recycling and the cost of process. The amount of ammonia used in the reaction may be preferably 10 moles or less based on one mole of ketone because there is a possibility that a large excess of ammonia to ketone may hinder the formation of hydrogen peroxide. In addition, the upper limit of the concentration of ammonia in the liquid phase of the reaction mixture is not particularly restricted, but it is generally preferably 15% by weight or less.

In the present specification, the term “ammonia” used in the general description means ammonia (NH₃) and ammonium ion (NH₄ ⁺; including dissociated ion and undissociated ion) supplied by any of ammonia sources. When “ammonia” is used to mean gaseous ammonia, liquid ammonia, or ammonia in solution, the meaning will be understood from the context.

Oxygen is supplied as molecular oxygen, i.e. oxygen gas. Air is also usable. The supply amount of oxygen is generally 0.1 to 20 times by mole and preferably 1 to 10 times by mole based on the amount of ketone. Hydrogen is also supplied as hydrogen gas. The supply amount of hydrogen is generally 0.1 to 10 times by mole and preferably 1 to 5 times by mole based on the amount of ketone.

From the view point of safety and disaster prevention, the composition of the reaction system is preferably selected so as to be out of explosive range of hydrogen, and thus the system is preferably diluted with diluent gas. For this reason, at least one of, preferably both of oxygen and hydrogen may be diluted with a diluent gas (carrier gas) and supplied to the system. Examples of diluent gas include nitrogen, argon, helium, neon, methane, ethane, propane, carbon dioxide, air and the like, but preference is given to nitrogen, carbon dioxide and air. In case that the explosive range is avoided by the concentration of hydrogen, the concentration of hydrogen is generally less than 4.0% by volume in the supplied gas, and therefore the supply amount of the diluent gas is chosen so that the mixture has such component composition.

In the present invention, it is preferred to add an appropriate amount of carbon dioxide into the ammoximation reaction system because it enables the production of oxime with high yield and with high selectivity. Carbon dioxide may be added in various forms. As the form of carbon dioxide (i.e. source of carbon dioxide) to be added into the reaction, carbon dioxide gas and carbonate salts are exemplified. When carbon dioxide gas is used as a source of carbon dioxide, carbon dioxide gas is preferably used as at least a part of diluent gas, for example, at least a part of carrier gas of oxygen and/or hydrogen. As carbonate salts, ammonium carbonate, ammonium hydrogen carbonate (ammonium bicarbonate) and the like may be used. Ammonium carbonate and ammonium hydrogen carbonate are preferred because they function as sources of ammonia as mentioned before. Addition of one mole of ammonium carbonate or ammonium hydrogen carbonate is counted as the addition of one mole of carbon dioxide. In addition, carbon dioxide can be added in combination of these methods.

The amount of carbon dioxide added to the system, namely a total amount of carbon dioxide gas and carbonate salt (ammonium carbonate, ammonium hydrogen carbonate), is more than 0, preferably 0.1 times by mole or more and less than 10 times by mole, and more preferably, 0.5 times by mole or more and 5 times by mole or less, based on the total amount of ammonia. Herein, the total amount of ammonia is a sum of all ammonia component contained in ammonia solution, ammonia gas and ammonium salt (ammonium carbonate, ammonium hydrogen carbonate) supplied into the system. Herein, in the present specification, the term “carbon dioxide” used in the general description means carbon dioxide (CO₂₎, carbonate ion (CO₃ ^2-; including dissociated ion and undissociated ion) and hydrogen carbonate ion (HCO₃ ^-; including dissociated ion and undissociated ion) supplied by any of carbon dioxide sources.

The best result is obtained if the ammoximation catalyst of the present invention is used and an appropriate amount of carbon dioxide is added into the ammoximation reaction system. However, even if catalysts inferior to the catalyst of the present invention are used, the addition of an appropriate amount of carbon dioxide into the ammoximation reaction system enables the production of oximes with high yield and high selectivity. Thus, one aspect of the present invention, namely a process for producing an oxime by ammoximation reaction with addition of an appropriate amount of carbon dioxide, can be established as an independent invention.

In this case, a preferred catalyst comprises (a) a titanosilicate and a metal supported on the titanosilicate and/or another support that is different from the titanosilicate. The metal preferably comprises at least one metal selected from the group consisting of palladium, gold, platinum, silver, ruthenium, rhodium, osmium, iridium and rhenium, in particular preferably at least palladium. In addition to palladium, the catalyst may comprise at least a metal selected from the group consisting of gold, platinum, ruthenium, rhodium, osmium, iridium, rhenium, silver, copper, nickel, tin, cobalt and manganese. As the metal used with palladium, preference in given to one or more metals particularly selected from gold, platinum, nickel, tin, rhenium, osmium, copper and iridium, more preferably one or more selected from gold, platinum, nickel and tin, and most preferably one or more selected from gold and platinum. Materials and preparation method thereof are selected in a similar manner that is already described for the catalyst of the present invention.

Ammoximation reaction may be carried out in a solvent. Examples of the reaction solvents that may be used include, for example, aromatic compounds such as benzene and toluene; alcohols such as methyl alcohol, ethyl alcohol, n- propyl alcohol, isopropyl alcohol, n- butyl alcohol, s- butyl alcohol, t-butyl alcohol, and t-amyl alcohol; and water. Among these, alcohols and water are suitable. In particular, ammoximation reaction is preferably carried out in a mixed solvent of alcohol(s) and water.

In the present invention, it is also possible to add ions such as sulfate ion, phosphate ion, pyrophosphate ion, stannate ion, chloride ion, and bromide ion; acids such as aqueous hydrochloric acid solution, aqueous hydrobromic acid, aqueous phosphoric acid, aqueous sulfuric acid, aqueous nitric acid, tungstic acid and heteropolyacids; chelate compounds such as ethylenediamine tetra(methylene phosphonic acid), ethylenediaminetetraacetic acid, and nitrilotriacetic acid; other organic compounds such as organic hydroxy compounds, diglycolic acid, aromatic sulfonic acids, acyl phosphonic acids, phenanthroline, amino-triazine, and acetanilide; radical scavengers such as nitrone compounds, nitroso compounds, dithiocarbamate derivatives, and ascorbic acid derivatives; metal compounds such as tantalum species, zirconium species, and niobium species, in order to suppress the decomposition of the produced hydrogen peroxide.

The ammoximation reaction may be carried out in batch reaction, semi-batch reaction or continuous reaction. When the ammoximation reaction is carried out in batch or semi-batch reaction, the reaction may be carried out, for example, by adding ketone, source of ammonia (ammonia or ammonium salt), catalyst, and solvent in a reactor, and injecting hydrogen and oxygen, both diluted with diluent gas, up to a predetermined pressure. Or, the reaction may be carried out by adding ketone, catalyst, and solvent in a reactor, and supplying ammonia source, and hydrogen and oxygen, both diluted with diluent gas. Herein, a part of or all of ammonia source may be added in the reactor in advance.

When the ammoximation reaction is carried out in continuous reaction, the reaction may be carried out, for example, by supplying ketone, ammonia source, solvent and hydrogen and oxygen, both diluted with diluent gas, into a reactor in which a reaction mixture containing a catalyst dispersed therein is present; and taking out a liquid phase from the reactor via filter or the like. Or, the reaction may be carried out by supplying ketone, ammonia source, solvent and hydrogen and oxygen, both diluted with diluent gas, to a catalyst layer disposed in a reactor. The reactors preferably employed are those having lining of polytetrafluoroethylene or glass or those formed of stainless steel.

The reaction temperature of ammoximation reaction is generally 0 to 150 °C, preferably 50 to 120°C, more preferably 70 to 100°C. The reaction pressure is generally in the range of 0.1 to 20 MPa, preferably 1 to 10 MPa as expressed in gauge pressure. Reaction time is not particularly limited, but it is for example, 10 minutes to 24 hours, preferably 30 minutes to 12 hours.

Post-processing operation of obtaining an oxime as a target material from a reaction mixture after the ammoximation reaction is appropriately selected from the method known in the art. For example, the separation of oxime may be performed by removing the catalyst from the reaction mixture by filtration, centrifugation or decantation, and distilling the liquid phase.

Herein below, the present invention will be described in details by showing examples and comparative examples, but the present invention is not limited to the following examples.

<Example Part A>
In the Example Part A, it will be shown that the catalysts of an aspect of the present invention are superior to conventional catalysts.

Example A1
(Preparation of Catalyst A1) Au-Pd catalyst
0.53 g of 2.1 wt% HAuCl₄ aqueous solution, 1.1 g of 1.0wt% PdCl₂ aqueous solution dissolved with diluted aqueous hydrochrolic acid, and 23 g of water were mixed, into which 2.0 g of titanosilicate (TS-1, Si/Ti atomic ratio 30) available from ACS-MATERIAL was dispersed. While stirring with a magnetic stirrer, the mixture was heated to about 85°C to remove water until it became a semi-liquid state. Subsequently, the mixture was fully dried at the same or higher temperature, and the resultant dried mixture was crushed and calcined at 400°C for 3 hours under ambient atmosphere to obtain 2.0 g of gray powdery catalyst as Catalyst A1. The amounts of the metal precursors were adjusted so that the supported amount of both gold and palladium became 0.33 wt %.

(Ammoximation reaction) Evaluation by Reaction Condition 1
(Reaction Condition 1) NH₄HCO₃ is present, diluent gas is nitrogen gas
To an autoclave having a capacity of about 100mL, 2 mmol of cyclohexanone, 5.9g of t-butyl alcohol, 7.5g of water and 4 mmol of ammonium hydrogen carbonate were charged. The solution had pH of 8.3. To the autoclave, 0.075 g of a catalyst (in this case, Catalyst A1 prepared above) was charged, and a mixed gas having a composition of 23% oxygen and 77% nitrogen was fed up to a pressure of 1.1 MPa, then, a mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed so that the total pressure became 4.0 MPa. The inner temperature of the autoclave was controlled at 80°C and the mixture in the autoclave was stirred to initiate the reaction. Liquid phase was taken out at 6 hours after the initiation of the reaction, and analyzed by gas chromatography. The results showed that the conversion of cyclohexanone (X_ON) was 98%, the selectivity of cyclohexanone oxime (S_ON) was 99%, and the yield of cyclohexanone oxime (Y) was 97%. In addition, gas phase after the reaction was collected and analyzed. The result showed that the hydrogen-basis selectivity of oxime (S_H2) was 65%. The residual ammonia in the liquid phase was analyzed by acid-base titration, and the result showed that ammonia-basis (ammonium hydrogen carbonate-basis) selectivity of oxime (S_NH3) was 85%. The results were also shown in Table A1.

Example A2
(Preparation of Catalysts A2 to A5)
Catalysts A2 to A5 were prepared in the same manner as the preparation of Catalyst A1 except that supporting amounts (wt%) of gold and palladium were changed as shown in Table A1. Ammoximation reactions were carried out by using Catalysts A2 to A5, in which Reaction Condition 1 was employed for the reaction as employed in Example A1. The results are shown in Table A1.

Example A3
(Preparation of Catalysts A6 to A10)
Catalysts A6 to A10 were prepared in the same manner as the preparation of Catalyst A1 except that supporting amounts (wt%) of gold and palladium were changed as shown in Table A2. Catalysts A1 and A6 to A10 were evaluated in terms of the performance in ammoximation reaction by employing the following Reaction Condition 2.

(Reaction Condition 2) NH₄HCO₃ is present, diluent gas is CO₂
To an autoclave having a capacity of about 100mL, 2 mmol of Cyclohexanone, 5.9g of t-butyl alcohol, 7.5g of water and 4 mmol of ammonium hydrogen carbonate were charged. To the autoclave, 0.075 g of a catalyst was charged, and a mixed gas having a composition of 5% hydrogen and 95% carbon dioxide was fed up to a pressure of 2.9 MPa, then, a mixed gas having a composition of 25% oxygen and 75% carbon dioxide was fed so that the total pressure became 4.0 MPa. The inner temperature of the autoclave was controlled at 80°C and the mixture in the autoclave was stirred to initiate the reaction. Analytical results at 6 hours after the initiation of the reaction were shown in Table A2.

Example A4
(Preparation of Catalysts A11 to A14) Au-Pd-Pt Catalysts
Catalysts A11 to A14 containing gold, palladium and platinum were prepared similarly to the preparation of Catalyst A1 so that the supported amounts of the metals became as shown in Table A3. Herein, H₂PtCl₆ was used as a platinum source. Ammoximation reaction was carried out to evaluate the catalyst, in which Reaction Condition 1 was employed as employed in Example A1. The results are shown in Table A3.

Example A5
(Preparation of Catalyst A15) Other tri-metallic Catalysts
Catalyst A15 containing gold, palladium and rhodium was prepared similarly to the preparation of Catalyst A1 so that the supported amounts of the metals became as shown in Table A4. Herein, RhCl₃ was used as a rhodium source. Ammoximation reaction was carried out to evaluate the catalyst, in which Reaction Condition 1 was employed as employed in Example A1. The results are shown in Table A4.

Example A6
(Preparation of Catalyst A16) TS-1 + 2.5%Au-2.5%Pd/TiO₂ Catalyst
A TiO₂-support catalyst in which gold and palladium were supported each in an amount of 2.5% by weight was prepared in the same manner as the preparation of Catalyst A1 except that titanium oxide was used as a support for the metal and the supporting amount was changed. 0.010 g of the obtained TiO₂-support catalyst and 0.075 g of titanosilicate (TS-1) were mixed to give Catalyst A16 and evaluated in terms of the performance in ammoximation reaction by employing Reaction Condition 1. The results are shown in Table A5.

Example A7
(Preparation of Catalyst A17) TS-1 + 2.5%Au-2.5%Pd/C Catalyst
An activated carbon-support catalyst in which gold and palladium were supported each in an amount of 2.5% by weight was prepared in the same manner as the preparation of Catalyst A1 except that activated carbon was used as a support for the metal and the supporting amount was changed. 0.010 g of the obtained activated carbon-support catalyst and 0.075 g of titanosilicate (TS-1) were mixed to give Catalyst A17 and evaluated in terms of the performance in ammoximation reaction.

As the ammoximation reaction, the reaction condition similar to Reaction Condition 2 was employed.
To an autoclave having a capacity of about 100mL, 2 mmol of Cyclohexanone, 8.4 g of t-butyl alcohol, 1.8 g of water and 4 mmol of aqueous ammonia solution were charged. To the autoclave, 0.075 g of Catalyst A17 (0.010 g of the activated carbon-support catalyst and 0.075 g of titanosilicate (TS-1)) was charged, and a mixed gas having a composition of 5% hydrogen and 95% carbon dioxide was fed up to a pressure of 2.9 MPa, then, a mixed gas having a composition of 25% oxygen and 75% carbon dioxide was fed so that the total pressure became 4.0 MPa. The inner temperature of the autoclave was controlled at 80°C and the mixture in the autoclave was stirred to initiate the reaction. Liquid phase was taken out at 3 hours after the initiation of the reaction, and analyzed by gas chromatography. The results are shown in Table A6.

Example A8
(Preparation of Catalyst A18) Au-Pd catalyst
0.53 g of 2.1 wt% HAuCl₄ aqueous solution, 1.1 g of 1.0 wt% PdCl₂ aqueous solution dissolved with diluted aqueous hydrochrolic acid, and 800 mL of water were mixed, into which 1 wt% polyvinyl alcohol (PVA) aqueous solution was added so that a weight ratio of PVA/(Pd and Au) became 1.2. While stirring with a magnetic stirrer, freshly prepared sodium borohydride (NaBH₄) aqueous solution was added into the mixture so that a molar ratio of NaBH₄/(Pd and Au) became 5. 2.0 g of titanosilicate (TS-1, Si/Ti atomic ratio 30) available from ACS-MATERIAL was dispersed into the metal colloid obtained after 30 minutes of stirring at room temperature. The pH of the mixture was adjusted to 1 to 2 by adding sulfuric acid. After 2 hours of stirring at room temperature, the slurry was filtered and the resultant solid was washed with water until the pH of mother liquors became neutral. The resultant solid was dried at 110°C for 16 hours in static air and then the dried solid was calcined at 400°C for 3 hours under ambient atmosphere to obtain 2.0 g of gray powdery catalyst as Catalyst A18. The amounts of the metal precursors were adjusted so that the supported amount of both gold and palladium became 0.33wt%.

(Ammoximation reaction)
Ammoximation reaction was carried out to evaluate the catalyst A18, in which the reaction conditions similar to Reaction Condition 1 was employed. To an autoclave having a capacity of about 100 mL, 2 mmol of cyclohexanone, 5.9 g of t-butyl alcohol, 7.5 g of water and 4 mmol of ammonium hydrogen carbonate were charged. To the autoclave, 0.075 g of a catalyst (in this case, Catalyst A18 prepared above) was charged, and a mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed up to a pressure of 2.9 MPa, then, a mixed gas having a composition of 25% oxygen and 75% nitrogen was fed so that the total pressure became 4.0 MPa. The inner temperature of the autoclave was controlled at 80°C and the mixture in the autoclave was stirred to initiate the reaction. Liquid phase was taken out at 3 hours after the initiation of the reaction, and analyzed by gas chromatography. The results showed that the conversion of cyclohexanone (X_ON) was 80%, the selectivity of cyclohexanone oxime (S_ON) was 82%, and the yield of cyclohexanone oxime (Y) was 66%.

Example A9
(Preparation of Catalysts A19 to A21)
Catalysts A19 to A21 were prepared in the same manner as the preparation of Catalyst A18 except that a weight ratio of PVA/(Pd and Au) was changed as shown in Table A7. Catalysts A19 to A21 were evaluated in terms of the performance in ammoximation reaction by employing the reaction conditions employed in Example A8. The results are shown in Table A7.

Example A10
(Preparation of Catalysts A22 to A25)
Catalysts A22 to A25 were prepared in the same manner as the preparation of Catalyst A18 except that the calcination temperature was changed as shown in Table A8. Catalysts A22 to A25 were evaluated in terms of the performance in ammoximation reaction by employing the reaction conditions employed in Example A8. The results are shown in Table A8.

Example A11
(Preparation of Catalysts A26 to A27) Au-Pd-Pt catalysts
Catalysts A26 to A27 containing gold, palladium and platinum were prepared similarly to the preparation of Catalyst A18 so that the supported amounts of the metals became as shown in Table A9. Herein, H₂PtCl₆ was used as a platinum source. Ammoximation reaction was carried out to evaluate the catalysts, in which the same reaction conditions were employed as employed in Example A8. The results are shown in Table A9.

Comparative Example A1
(Preparation of Comparative Catalysts A1-1 to A1-3) Pd Catalyst
Comparative Catalysts A1-1 to A1-3 containing palladium only in an amount of 0.33%, 0.66% and 2.5% by weight, respectively, supported on titanosilicate (TS-1) were prepared similarly to the preparation of Catalyst A1. Ammoximation reaction was carried out to evaluate Comparative Catalysts A1-1 to A1-3, in which Reaction Condition 1 was employed. The results are shown in Table A10 together with the results of Catalyst A1.

Comparative Example A2
(Preparation of Comparative Catalyst A2) Pd-Pt Catalyst
Comparative Catalyst A2 containing palladium and platinum each in an amount of 0.33% by weight supported on titanosilicate (TS-1) was prepared similarly to the preparation of Catalyst A1.
(Evaluation by Reaction Condition 1)
Ammoximation reaction was carried out to evaluate Comparative Catalyst A2, in which Reaction Condition 1 was employed. The results are shown in Table A10.

(Evaluation by Reaction Condition 2)
Ammoximation reaction was carried out to evaluate Comparative Catalyst A2 by employing the reaction condition similar to Reaction Condition 2 (CO₂ diluent gas). Namely, to an autoclave having a capacity of about 100mL, 2 mmol of Cyclohexanone, 5.9g of t-butyl alcohol, 7.5g of water and 4 mmol of ammonium hydrogen carbonate were charged. To the autoclave, 0.075 g of a catalyst was charged, and the following mixed gases were fed so as to have respective partial pressure; (i) 2.5 MPa of a mixed gas having a composition of 5% hydrogen and 95% carbon dioxide; (ii) 0.40 MPa of a mixed gas having a composition of 5% hydrogen and 95% nitrogen; (iii) 0.94 MPa of a mixed gas having a composition of 25% oxygen and 75% carbon dioxide; and (iv) 0.17 MPa of a mixed gas having a composition of 23% oxygen and 77% nitrogen. The inner temperature of the autoclave was controlled at 80°C and the mixture in the autoclave was stirred to initiate the reaction. Both liquid phase taken out and gas phase collected at 6 hours after the initiation of the reaction was analyzed. The results are shown in Table A11.

Comparative Example A3
(Preparation of Comparative Catalyst A3) Au Catalyst
Comparative Catalyst A3 containing only gold in an amount of 0.33% by weight supported on titanosilicate (TS-1) was prepared similarly to the preparation of Catalyst A1. Ammoximation reaction was carried out to evaluate Comparative Catalyst A3, in which Reaction Condition 1 was employed. The results are shown in the above Table A10.

Example A12
(Production of 2-butanone oxime)
In this example, the reaction was carried out by replacing cyclohexanone with 2-butanone in Example 1. Namely, to an autoclave having a capacity of about 100mL, 2 mmol of 2-butanone, 5.9g of t-butyl alcohol, 7.5g of water and 4 mmol of ammonium hydrogen carbonate were charged. To the autoclave, 0.075 g of Catalyst A1 was charged, and a mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed up to a pressure of 2.9 MPa, then, a mixed gas having a composition of 23% oxygen and 77% nitrogen was fed so that the total pressure became 4.0 MPa. The inner temperature of the autoclave was controlled at 80°C and the mixture in the autoclave was stirred to initiate the reaction. Liquid phase was taken out and gas phase was collected at 6 hours after the initiation of the reaction, and analyzed. The results showed that the yield of 2-butanone oxime was 62%, the hydrogen-basis selectivity of oxime was 47% and ammonium hydrogen carbonate-basis selectivity of oxime was 78%.

Example A13
(Production of cyclododecanone oxime)
In this example, the reaction was carried out by replacing cyclohexanone with cyclododecanone in Example 1. Namely, to an autoclave having a capacity of about 100mL, 2 mmol of cyclododecanone, 5.9g of t-butyl alcohol, 7.5g of water and 4 mmol of ammonium hydrogen carbonate were charged. To the autoclave, 0.075 g of Catalyst A1 was charged, and a mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed up to a pressure of 2.9 MPa, then, a mixed gas having a composition of 23% oxygen and 77% nitrogen was fed so that the total pressure became 4.0 MPa. The inner temperature of the autoclave was controlled at 80°C and the mixture in the autoclave was stirred to initiate the reaction. Liquid phase was taken out and gas phase was collected at 6 hours after the initiation of the reaction, and analyzed by gas chromatography and acid-base titration. The results showed that the conversion of cyclododecanone was 29%, the selectivity of cyclododecanone oxime was 89%, and the yield of cyclododecanone oxime was 26%. The hydrogen-basis selectivity of oxime was 26% and ammonium hydrogen carbonate-basis selectivity of oxime was 27%.

<Example Part B>
In the Example Part B, it will be shown that the process of an aspect of the present invention is superior to conventional processes.

Example B1
Unless otherwise mentioned, Catalyst A1 prepared in Example A1 is used in the following examples. Example B1 is the same as Example A1 and ammoximation reaction was carried out by employing Reaction Condition 1. Namely, 4 mmol of ammonium hydrogen carbonate was used as sources of ammonia and carbon dioxide, and nitrogen gas which does not contain carbon dioxide gas was used as carrier gases for supplying hydrogen and oxygen. The conditions and results are shown in Table B1.

Comparative Example B1
Ammoximation reaction was carried out as similar to Reaction Condition 1, except that aqueous ammonia solution was used as the ammonia source. Namely, to an autoclave having a capacity of about 100mL, 2 mmol of cyclohexanone, 5.9g of t-butyl alcohol, 4.8g of water and 2.8 g (4 mmol) of 2.4 wt%-aqueous ammonia solution were charged. The solution had pH of 11. Thereafter, in the same manner as Example A1, 0.075 g of Catalyst A1 was charged to the autoclave, and a mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed up to a pressure of 2.9 MPa, then, a mixed gas having a composition of 23% oxygen and 77% nitrogen was fed so that the total pressure became 4.0 MPa. The inner temperature of the autoclave was controlled at 80°C and the mixture in the autoclave was stirred to initiate the reaction. Liquid phase was taken out and gas phase was collected at 6 hours after the initiation of the reaction, and analyzed. The results, as well as the conditions, were shown in Table B1.

Example B2
Ammoximation reaction was carried out as similar to Reaction Condition 1, except that 0.4 mmol of ammonium hydrogen carbonate and aqueous ammonia solution containing 3.6 mmol of ammonia were charged as ammonia sources in place of 4 mmol of ammonium hydrogen carbonate. The results, as well as the conditions, were shown in Table B1.

Example B3
Ammoximation reaction was carried out as similar to Reaction Condition 1, except that 2.0 mmol of ammonium hydrogen carbonate and aqueous ammonia solution containing 2.0 mmol of ammonia were charged as ammonia sources in place of 4 mmol of ammonium hydrogen carbonate. The results, as well as the conditions, were shown in Table B1.

Example B4
In Reaction Condition 1, carbon dioxide was added. Namely, in the same manner as employed in Reaction Condition 1, cyclohexanone, t-butyl alcohol, water, ammonium hydrogen carbonate, and Catalyst A1 were charged. Into the autoclave, 4 mmol (0.12 MPa) of carbon dioxide was added. A mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed up to a partial pressure of 2.9 MPa, and a mixed gas having a composition of 23% oxygen and 77% nitrogen was fed up to a partial pressure of 1.1 MPa. Thereafter, the reaction was carried out in the same manner as Reaction Condition 1. Liquid phase was taken out and gas phase was collected at 6 hours after the initiation of the reaction, and analyzed. The results, as well as the conditions, were shown in Table B1.

Example B5
Reaction was carried out in the same manner as Example B4, except that 8 mmol (0.24 MPa) of carbon dioxide was added. The results, as well as the conditions, were shown in Table B1.

Example B6
In the same manner as employed in Reaction Condition 1, cyclohexanone, t-butyl alcohol, water, ammonium hydrogen carbonate, and Catalyst A1 were charged. Into the autoclave, a mixed gas having a composition of 25% oxygen and 75% carbon dioxide was fed up to a pressure of 1.1 MPa, then, a mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed so that the total pressure became 4.0 MPa. The moles of carbon dioxide used as a diluent gas correspond to 26 mmol. Thereafter, the reaction was carried out in the same manner as Reaction Condition 1. Liquid phase was taken out and gas phase was collected at 6 hours after the initiation of the reaction, and analyzed. The results, as well as the conditions, were shown in Table B1.

Comparative Example B2
In the same manner as employed in Reaction Condition 1, cyclohexanone, t-butyl alcohol, water, ammonium hydrogen carbonate, and Catalyst A1 were charged. Into the autoclave, a mixed gas having a composition of 5% hydrogen and 95% carbon dioxide was fed up to a pressure of 2.3 MPa, and further a mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed so that the total pressure became 2.9 MPa. Furthermore, a mixed gas having a composition of 23% oxygen and 77% nitrogen was fed so that the total pressure became 4.0 MPa. The moles of carbon dioxide used as a diluent gas correspond to 71 mmol. Thereafter, the reaction was carried out in the same manner as Reaction Condition 1. Liquid phase was taken out and gas phase was collected at 6 hours after the initiation of the reaction, and analyzed. The results, as well as the conditions, were shown in Table B1.

Comparative Example B3
In the same manner as employed in Reaction Condition 1, cyclohexanone, t-butyl alcohol, water, ammonium hydrogen carbonate, and Catalyst A1 were charged. Into the autoclave, a mixed gas having a composition of 5% hydrogen and 95% carbon dioxide was fed up to a pressure of 2.6 MPa, then, a mixed gas having a composition of 25% oxygen and 75% carbon dioxide was fed so that the total pressure became 3.5 MPa. The moles of carbon dioxide used as a diluent gas correspond to 101 mmol. Thereafter, the reaction was carried out in the same manner as Reaction Condition 1. Liquid phase was taken out and gas phase was collected at 6 hours after the initiation of the reaction, and analyzed. The results, as well as the conditions, were shown in Table B1.

Example B7
To an autoclave having a capacity of about 100mL, 2 mmol of cyclohexanone, 5.9 g of t-butyl alcohol, 4.8 g of water, 2.8 g (4 mmol) of 2.4 wt%-aqueous ammonia solution, and 0.075 g of Catalyst A1were charged. Into the autoclave, 4 mmol (0.12 MPa) of carbon dioxide was added. A mixed gas having a composition of 5% hydrogen and 95% nitrogen was fed up to a pressure of 3.0 MPa, and a mixed gas having a composition of 23% oxygen and 77% nitrogen was fed so that the total pressure became 4.1 MPa. Thereafter, the reaction was carried out in the same manner as Reaction Condition 1. Liquid phase was taken out and gas phase was collected at 6 hours after the initiation of the reaction, and analyzed. The results, as well as the conditions, were shown in Table B1.

From the above results, it is found that the addition of carbon dioxide enhances the reaction yield (Y) and the like. However, since too much use thereof results in decrease of the reaction yield (Y), the amount of carbon dioxide (total amount) is preferably less than 10 times by mole based on the amount of ammonia.

Example B8 and Comparative Example B4
By using Comparative Catalyst A2 prepared in Example Part A, influence of reaction conditions was evaluated, and the results are shown in Table B2. Example B8 and Comparative Example B4 is a reproduction of the results of Comparative Catalyst A2 in Reaction Condition 1 and Reaction Condition 2 shown in Example Part A. The results of Example B1 (Example A1) is also shown.

Comparative Example B5
The same reaction condition as Comparative Example B1 (i.e. no CO₂) was evaluated by using Comparative Catalyst A2, and the result is shown in Table B2.

It is confirmed that the process condition of the present invention is effective even if catalysts having inferior reaction performance are used. However, it should be noted that the catalyst of the present invention can achieve better results when compared in the same condition, as already demonstrated in Example Part A.

According to the present invention, oxime compounds are produced from various ketone compounds.

Claims

An ammoximation catalyst for producing an oxime from a ketone by ammoximation reaction using hydrogen, oxygen and ammonia, the catalyst comprising:
(a) a titanosilicate and
(b) a metal supported on the titanosilicate and/or another support that is different from the titanosilicate; the metal comprising palladium and gold.
The ammoximation catalyst according to claim 1, wherein a supporting amount of the metal is 0.01 to 20% by weight.
The ammoximation catalyst according to claim 1 or 2, wherein a weight ratio of gold/palladium is 0.02 to 50.
The ammoximation catalyst according to any one of claims 1 to 3, wherein a weight ratio of gold/palladium is 0.05 to 5.
The ammoximation catalyst according to any one of claims 1 to 4, wherein the metal further comprises at least one metal selected from the group consisting of platinum, ruthenium, rhodium, osmium, iridium, silver, rhenium, tin, cobalt, nickel, copper and manganese.
The ammoximation catalyst according to any one of claims 1 to 5, wherein the titanosilicate comprises TS-1.
The ammoximation catalyst according to any one of claims 1 to 6, wherein the support for the metal is selected from the group consisting of titanium oxide, activated carbon, silica, alumina and iron oxide.
A process for producing an oxime from a ketone by ammoximation reaction using hydrogen, oxygen and ammonia in a presence of an ammoximation catalyst, the process comprising the step of:
performing the ammoximation reaction by supplying carbon dioxide in an amount of more than 0 and less than 10 times by mole based on an amount of ammonia.
The process according to claim 8, wherein carbon dioxide is supplied in an amount of 0.1 times by mole or more and less than 10 times by mole, based on an amount of ammonia.
The process according to claim 8 or 9, wherein carbon dioxide is supplied in an amount of 0.5 to 5 times by mole, based on an amount of ammonia.
The process according to any one of claims 8 to 10, wherein a form of ammonia supplied to the reaction is selected from aqueous ammonia solution, gaseous ammonia, ammonium salts, and combination of two or more of these.
The process according to claim 11, wherein at least a part of ammonia supplied to the reaction is in a form of ammonium salt, and the ammonium salt is at least one of ammonium carbonate and ammonium hydrogen carbonate.
The process according to any one of claims 8 to 12, wherein a form of carbon dioxide supplied to the reaction is selected from carbon dioxide gas, carbonate salts, and combination of two or more of these.
The process according to claim 13, wherein at least a part of carbon dioxide supplied to the reaction is in a form of carbonate salt, and the carbonate salt is at least one of ammonium carbonate and ammonium hydrogen carbonate.
The process according to any one of claims 8 to 14, wherein the ammoximation catalyst comprises:
(a) a titanosilicate and
(b) a metal supported on the titanosilicate and/or another support that is different from the titanosilicate.
The process according to claim 15, wherein the metal comprises palladium or a combination of palladium and one or more metals selected from the group consisting of gold, platinum, nickel, tin, rhenium, osmium, copper, iridium, ruthenium, rhodium, silver, cobalt and manganese.