The catalyst for vinyl acetate containing metal palladium, copper and gold, and its getting

 

The invention relates to catalysts for production of vinyl acetate by reaction of ethylene, oxygen and acetic acid. Describes a catalyst to obtain a vinyl acetate by reaction of ethylene, oxygen and acetic acid containing porous media, porous surfaces of which is deposited catalytically effective amounts of metallic palladium, gold and copper, with the above-mentioned catalyst was prepared in stages, including the impregnation of said carrier, a porous surface which contains a catalytically effective amount previously recovered palladium and copper, a solution of Aurat potassium and restore Aurat potassium to catalytically effective amount of metallic gold. Alternative media can first be brought into contact with the gold, followed by contact with complexes of palladium/copper. The technical effect of improving the performance of vinyl acetate by using a catalyst having a lower selectivity for carbon dioxide and heavy fractions. 4 C. and 22 C.p. f-crystals, 1 table.

Field of invention the Invention relates to new and improved catalysts for production of vinyl acetate by reaction of these the techniques Known to produce vinyl acetate by reaction of ethylene, oxygen and acetic acid using a catalyst consisting of metallic palladium, gold and copper supported on a carrier. Despite the fact that the way in which the use of such a catalyst, it is possible to obtain vinyl acetate with sufficient levels of performance, it is obvious that the preferred any technique by which you can achieve even better performance with the use of the catalyst, which in some respects is easier to get than the one that was used until now.

Known until the present invention, the catalyst containing metallic palladium, gold and copper, are usually obtained by the process comprising a stage of impregnation of porous media one aqueous solution or separate solutions of water-soluble salts of palladium, gold and copper; the interaction of the absorbed water-soluble salts with an appropriate alkaline compound, for example sodium hydroxide, to "lock" these metal elements in the form of water-insoluble compounds, such as hydroxides; and recovery of water-insoluble compounds, such as ethylene or hydrazine, to transfer the metal elements in the free metal form. This type of process has not settled.

For stated herein of the invention can be essential the following links. In U.S. patent 5332710, issued July 26, 1994, Nicolau et al., disclosed is a method of obtaining a catalyst for production of vinyl acetate by reaction of ethylene, oxygen and acetic acid, comprising the impregnation of porous media, water-soluble salts of palladium and gold, hold on medium of palladium and gold in the form of insoluble compounds by dipping and rolling the impregnated carrier in the reaction solution for the deposition of these compounds and subsequent recovery of these compounds in the free metal form.

In U.S. patent 5347046, issued September 13, 1994, White et al., disclosed catalysts for vinyl acetate by reaction of ethylene, oxygen and acetic acid containing a metal of the group of palladium and/or its connection, gold and/or its connection, and copper, Nickel, cobalt, iron, manganese, lead or silver, or their compounds, preferably deposited on a material carrier.

In the United Kingdom patent 1188777, published on April 22, 1970, disclosed a method of simultaneous receipt of ester of unsaturated carboxylic acids, for example vinyl acetate, by reaction of an olefin, a carboxylic acid and oxygen, and shooter on the media, containing a compound of palladium, such as the oxide or salt, and one or more compounds of any of various metals, such as metallic gold, or a combination of gold, for example, such as Aurat potassium.

In U.S. patent 5700753 disclosed catalyst for vinyl acetate (VA), obtained by addition of ORGANOMETALLIC complexes of gold to the previously restored palladium catalyst, obtained from Na2PdCl4. For ORGANOMETALLIC compounds of gold does not require the process of fixing.

In U.S. patent 5731457 described VA catalyst based on copper compounds not containing halogen.

Brief description of the invention In accordance with the invention provided the catalyst to obtain a vinyl acetate by reaction of ethylene, oxygen and acetic acid with a low selectivity for carbon dioxide, and the above-mentioned catalyst obtained in stages, comprising impregnating a porous support, the porous surfaces of which contain a catalytically effective amount previously recovered palladium and copper, a solution of Aurat potassium (KaAuO2and restore Aurat potassium to catalytically effective amount of metallic gold. Alternative e, with subsequent impregnation, recording and recovery of complexes of Pd and si on the media. The use of such a catalyst often leads to lower selectivity for carbon dioxide and heavy fractions, which is usually accompanied by higher performance vinyl acetate than using various conventional catalysts containing metallic palladium and gold.

As another alternative, it is possible to obtain a catalyst with the use of reagents that do not contain sodium. For example, you can use potassium salts described here reagents.

Detailed description of the invention In accordance with this invention provided the catalyst for production of vinyl acetate by reaction of ethylene, oxygen and acetic acid with a low selectivity for carbon dioxide, and the said catalyst contains a porous carrier, which is deposited catalytically effective amounts of metallic palladium, gold and copper, these catalyst obtained in stages, including (1) the impregnation of the support of catalytically effective amounts of a water-soluble solutions of palladium and copper, with subsequent fixation and recovery of Pd and si to their metallic form; (2) contact ATA potassium to catalytically effective amount of metallic gold.

Alternative media can (1) first, to bring into contact with a solution of Aurat potassium, repair Aurat potassium to catalytically effective amount of metallic gold and (2) to bring into contact with a catalytically effective amounts of a water-soluble solutions of palladium and copper with subsequent recovery of Pd and si to their metallic form.

The use of the catalysts of the invention often results in lower selectivity for carbon dioxide, which is usually accompanied by a higher level of performance vinyl acetate than using various conventional catalysts containing metallic palladium and gold.

The material of the catalyst carrier consists of particles having any right or wrong forms, such as spheres, tablets, cylinders, rings, stars or other shapes, and may have dimensions such as diameter, length or width, comprising from about 1 to about 10 mm, preferably from about 3 to about 9 mm. are Preferred sphere of diameter from about 4 to about 8 mm, the Material of the carrier may consist of any suitable porous material, for example silica, alumina, silica - alumina, titanium dioxide, di the media can have a density, in the interval, for example, from about 0.3 to about 1.2 g/ml, the absorbent capacity in the range of from about 0.3 to 1.5 g2O/g carrier, the surface area in the range of, for example, from about 10 to about 350, preferably from about 100 to about 200 m2/g, the average pore size in the range of, for example, from about 50 to about 2000 angstroms and a pore volume in the range of, for example, from about 0.1 to about 2, preferably from about 0.4 to about 1.2 ml/g

Upon receipt of the catalyst used in the method of the present invention, the material of the carrier of the first process for deposition on the porous surface of the carrier particles of catalytic amounts of palladium and copper. For this purpose you can use any of various methods, which include a carrier impregnated with an aqueous solution of water-soluble compounds, for example salts of palladium and copper. Examples of suitable water-soluble palladium compounds are palladium (II) chloride, palladium (II) chloride of sodium, that is, palladium (II) tetrachloride sodium (Na2PdCl4), palladium (II) tetrachloride, potassium nitrate, palladium (II) or sulfate, palladium (II), then as a water-soluble copper compounds can be used chloride of copper (II), anhydrous or dihydrate, predpochtitelnye salts for impregnation are palladium (II) tetrachloride sodium and chloride copper (II) due to its good solubility in water. The impregnation can be carried out by the method of the "initial wetting", in which the amount of solution of water-soluble compounds of the metal used for impregnation is from about 95 to about 100 percent of the absorption capacity of a material medium. The concentration of this solution is that the number of elemental palladium and copper in solution, absorbed on a carrier, was equal to a predetermined number. Impregnation is to provide, for example, from about 1 to about 10 grams of elemental palladium and, for example, from about 0.3 to about 5.0 grams, preferably from about 0.5 to about 3.0 g of elemental copper per liter of the final catalyst.

After impregnation of the carrier with an aqueous solution of water-soluble compounds of palladium and copper, these compounds "fix" that is precipitated in the form of water-insoluble compounds, such as hydroxides by reaction with an appropriate alkaline compound, for example an alkali metal hydroxide, silicate, borate, carbonate or bicarbonate, in aqueous solution. The hydroxides of potassium and sodium are preferred locking alkaline compounds. Alkali metal must be contained in the alkaline compound in the amount of, for example, from about 1 to about what eticheski active cations, present in soluble salts. Fixation of palladium and copper can be made by the method of initial wetting, in which the impregnated carrier is dried, for example at a temperature of 150oC for one hour, put in contact with a solution of alkaline compounds, approximately 95-100% of the pore volume of the media, and allowed to stand for a period of time of about 1/2 hour to about 16 hours; or recommissioned way in which the impregnated carrier without drying is immersed in a solution of alkaline compounds and rotate and/or overturn during at least the initial period of the deposition so that the surface of the particle carrier or near it produces a thin strip of precipitated water-soluble compounds. Rotate or flip can be performed, for example, in the range of from about 1 to about 10 rpm for at least about 0.5, preferably from about 0.5 to about 4 hours. Estimated Roto-immersion method described in U.S. patent 5332710, the full disclosure of which is incorporated herein by reference.

After this fixed connection of palladium and copper can be recovered, for example, in the gas phase ethylene, for example, 5% in nitrogen at 150oIn teenage exemption from anions, such as the halide, and drying, for example, if 150oWith during the night with the constant blowing of N2or this recovery can be accomplished in the liquid phase at room temperature in an aqueous solution of hydrazine hydrate, where the excess of hydrazine in excess of that required to restore all of the metal compounds present on the carrier is in the range of, for example, from about 8:1 to about 15:1, followed by washing and drying. For recovery are fixed on the carrier compounds of palladium and copper, you can use other reducing agents, which are common in this area. Recovery of fixed connections leads mainly to the formation of free metal, but may also be present minor amounts of oxides of metals.

Although impregnation, fixation and recovery of palladium and copper have been described as carried out at the same time, these three phases, in fact, can be done separately for palladium and copper.

After receiving any of the methods previously described in the media containing palladium and copper in their free metallic form, it is impregnated with the aqueous solution of Aurat potassium, preferably by initial UVLO is to ensure, for example, from about 0.5 to about 10 g of elemental gold per liter of the final catalyst, the amount of gold constituting from about 10 to about 125 wt.% based on the weight of palladium present. Then Aurat potassium reduced to metallic gold by using any of the techniques previously described for the recovery of palladium and copper from fixed compounds of palladium and copper on the surface of the carrier. When carrying out such repair Aurat potassium there is no need for intermediate stages of fixation gold on the media in the form of water-insoluble compounds and washing of such connection to its full exemption from chloride ions, as described above for palladium, and that is usually necessary for gold upon receipt of the catalysts for vinyl acetate containing palladium and gold. An exception similar to the stages of fixation and washing in connection with gold is an important advantage in obtaining the catalyst of this invention.

One of the problems in obtaining VA catalysts was low retention of noble metal on the catalyst carrier. Use Kaayo2predecessors, offers a method of obtaining highly dispersed metal particles, the AI for AI is to increase retention of gold, because by known methods AI partially washed away from the catalyst during the stage of fixing/washing. In this way it is possible to obtain a catalyst with a high retention of gold. The catalyst also contains cu, Pd, AU, distributed in a thin layer on the surface of the catalyst carrier or near it.

Despite the fact that the catalysts of this invention have been described primarily in connection with catalysts containing as catalytically active metals, only palladium, gold and copper, the catalyst may also contain one or more catalytically active metal elements in the form of free metal, oxide or mixture of free metal and oxide. These metallic elements can represent, for example, magnesium, calcium, barium, zirconium and/or cerium. If the catalyst is desirable any metal in addition to palladium, gold and copper, the media usually can be impregnated with a water-soluble salt of the metal dissolved in the same solution used for impregnation, the solution containing soluble salts of palladium and copper. Thus, the carrier can be impregnated with a water-soluble salts of palladium, copper and an additional metal, which then ignoreme the additional metal. After that, the catalyst containing copper and palladium in the form of free metal, and more metal oxide and/or free metal impregnated awrah of potassium, which is then reduced to gold in the form of free metal, without the intermediate stage of fixation, as described previously in connection with copper and palladium as the only other metals in addition to gold.

Mainly the catalyst containing palladium, gold and copper in the free metal form, can optionally be impregnated with a solution of acetate of an alkali metal, preferably potassium acetate or sodium, and most preferably potassium acetate (COAs). After drying the final catalyst may contain, for example, from about 10 to about 70, preferably from about 20 to about 60 g of the acetate of alkali metal per liter of the final catalyst.

Optionally, the catalyst pre-restored Pd/Cu KaAuO2you can add together with COAs at one stage.

Upon receipt of vinyl acetate using a catalyst of the present invention over the catalyst pass the gas stream containing ethylene, oxygen or air, acetic acid and, preferably, alkali metal acetate. The composition of Noah, the ratio of ethylene and oxygen may range from about 80:20 to about 98:2, the molar ratio of acetic acid and ethylene may be from about 100:1 to about 1:100, preferably from 10:1 to 1:10 and most preferably from about 1:1 to about 1: 8, and the content of gaseous alkali metal acetate may be from about 1 to about 100 parts per million based on the used mass of acetic acid. In addition, the gas stream may contain other inert gases such as nitrogen, carbon dioxide and/or saturated hydrocarbons. The reaction temperature that can be applied, are elevated temperatures, preferably temperatures in the range of approximately 150-220oC. the Applied pressure can be up to certain limits reduced pressure, normal pressure or increased pressure, preferably a pressure of up to about 20 excess atmospheres.

Further, the invention is illustrated by the following examples.

Examples 1-12.

These examples illustrate the obtaining of the catalysts according to this invention, containing variable amounts of palladium and gold in the form of free metals.

Material media containing pre-reduced metal palladium was prepared as follows.

Material Novosti about 0,562 g/ml and an absorbent capacity of approximately 0,583 g H2O/g carrier, the surface area of from about 160 to about 1752/g and a pore volume of about 0.68 ml/g, was impregnated first with the initial wetting of 82.5 ml of aqueous solution of palladium (II) tetrachloride gold (Na2PdCl4) and copper chloride (II) (ul2), which is sufficient to provide about 7 grams of elemental palladium and about 1.9 grams of elemental copper per liter of catalyst. The media was dissolved in the solution for 5 minutes to ensure complete absorption of the solution. After that, palladium and copper are recorded on the media in the form of hydroxides of palladium (II) and copper (II) contacting the treated media by recommerce for 2.5 hours at approximately 5 rpm with 283 ml of an aqueous solution of sodium hydroxide obtained from the 50% mass/mass of NaOH/H2Oh, in the amount of 120% of the required for the conversion of the palladium and copper in their hydroxides. The solution was decanted from the treated media, which is then washed with deionized water to remove chloride ions (about 5 hours) and dried overnight at 150oWith constant purging with nitrogen. After that, palladium and copper are restored to the free metal by contact of the medium with ethylene (5% in nitrogen) in the gas phase at 150oC for 5 hours or hydrazino is in and drying in an oven at 150oC for 5 hours to obtain a carrier containing a nominal amount, representing 7 g/l previously restored Pd and 1.9 g/l previously recovered copper.

Upon receipt of the awrah of potassium used for impregnation of the carrier with gold, first prepared hydroxide gold, AU(OH)3when mixing 300 g of gold (III) tetrachloride sodium, NaAuCl4containing 0.20 g AI/g solution and 73,6 g of 50% mass/mass of NaOH/H2Oh, dissolved in 200 ml deionized water. Added an excess of NaOH to bring the pH to approximately 8 and mixed, and the solution was heated to 60oWith over 3 hours for the formation of an orange precipitate. Filtering allocated orange solid, which was washed with deionized water to remove chloride ions and dried in a vacuum oven at 50oWith the current N2to obtain an orange-red solid AI(OH)3. Analysis of this solid showed that the gold content is of 79.5 wt.%, which agrees with the calculated value.

The hydroxide of gold in the amount of 0.5 g was mixed with 0.12 g of KOH in 35 ml of water and heated received the orange suspension to a temperature of 82-85oC and stirred at this temperature until dissolution of all to elemental gold. This solution was added to 100 ml of media containing nominal amount of 7 g/l previously restored Pd and 1.9 g/l pre-recovered si, obtained by the method described above, using ethylene as a reducing agent. The impregnation was carried out for 25-30 minutes. The catalyst was dried in an oven at 100oC for 5 hours in a stream blown N2. After that, the gold in the treated catalyst was restored 5% ethylene in N2if 120oC for 5 hours to obtain the carrier free of metallic gold.

Finally, the catalyst was impregnated by the initial wetting with an aqueous solution containing 4 g of potassium acetate in 33 ml of N2O, and dried in a drying plant with fluidized bed under 100oC for 1 hour.

The previous description of the preparation of the catalyst according to this invention relates to catalysts of examples 1 to 3, which contain a nominal amount, that is, corresponding to the concentrations and quantities of the solutions used for impregnation, comprising 7 g of Pd, 1,9 g C and 4 g AI per liter of catalyst, and in which Pd, and si, and AI restore ethylene. In example 4, followed the methods of examples 1-3 except that the amount of materials the national amounts of copper, palladium and gold as the catalyst of examples 1-3. The catalysts of examples 5 through 12, which may contain the amount of Pd, cu and/or AU, is different from the quantities of examples 1-3 were obtained in a similar manner except that the concentration of Na2PdCl4, CuCl2and/or Kaayo2in the appropriate solution for impregnation changed to get on the media desired nominal amounts of Pd, cu and/or AU, and the recovery of each of the Pd, si and AI was performed either ethylene or hydrazine, as described previously. Used to obtain a reducing agent (Voss.) (C2H4or N2H4), the nominal amount of Pd, si and AI, corresponding to the concentrations and quantities of the solutions used for impregnation (nom., quantity, g/l), and the actual amount of Pd, si and AI on the catalysts of examples 1-12, defined as a result of the analysis, within the percentage of the catalyst as a whole, including the media (% of total cat.) and a percentage of nominal amounts (% of the rated quantity), presented in the table.

The catalysts of these examples were investigated for their activity and selectivity for various byproducts in the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid.and the stainless steel mesh with possibility of temperature measurement using thermocouples as above, so below this grid. The grid was placed in the reactor Bertie recirculation type with continuous stirring and kept at a temperature of providing about 45% conversion of oxygen by means of the electric heater casing. Through the mesh missed a gas mixture consisting of about 50 normal liters (measured at NTD) of ethylene, about 10 normal liters of oxygen, about 49 normal liters of nitrogen, 50 g of acetic acid and about 4 mg of potassium acetate, under a pressure of about 12 atmospheres, and the catalyst was getting old in these reaction conditions, at least 16 hours, up to two-hour mode, after which the reaction was completed. Analysis of the products was carried out using gas chromatographic analysis of the flow in conjunction with the analysis of liquid products outside of the flow or the flow of products at approximately 10oFor optimal analysis of the final products of carbon dioxide (CO2), heavy fractions (TF) and ethyl acetate (EtOAc), the results of which are used to calculate the selectivity of these substances for each example (Ave), as shown in the table. The relative activity of the reaction, expressed in the form factor activity (act.), also the developments correlating factor activity temperature of the catalyst during the reaction), the conversion of oxygen and a number of kinetic parameters of reactions during the synthesis of the VA. In a more General sense, the activity factor is inversely proportional to the temperature necessary to achieve permanent conversion of oxygen.

The values given in the table show that the catalysts of the invention in many cases can be used for the synthesis of vinyl acetate by reaction of ethylene, oxygen and acetic acid with a lower selectively on CO2and heavy fractions than in the case of different conventional and/or industrial catalysts containing palladium and gold, while at the same time satisfactory levels of activity.

Example 13 Obtaining catalyst for VA impregnation (1) KaAuO2followed by (2) Pd or Pd/Cu.

Obtaining catalyst for VA impregnation (1) KaAuO2followed by (2) Pd/Cu.

The material of the carrier in the amount of 100 ml, consisting of spheres of silicon dioxide Sud Chemie KA-160, having a nominal diameter of 7 mm, a density of about 0,562 g/ml, an absorbent capacity of approximately 0,583 g H2O/g carrier, the surface area of from about 160 to about 1752/g and a pore volume of about 0.68 ml/g, was impregnated it is sufficient to provide approximately 4 g of elemental gold per liter of catalyst. The media was dissolved in the solution for 5 minutes to ensure complete absorption of the solution. The treated carrier was placed in an oven and dried for 5 hours at 100oWith constant blowing of N2. The restoration was carried out using 5%2H4in N2if 120oC for 5 hours. Then, this catalyst with a pre-restored gold has infiltrated the method of initial moisture 35 ml of aqueous solution of palladium (II) tetrachloride sodium (Na2PdCl4) and copper chloride (II) (CuCl2), which is sufficient to provide about 7 grams of elemental palladium and about 1.9 grams of elemental copper per liter of catalyst. The media was dissolved in the solution for 5 minutes to ensure complete absorption of the solution. After that, palladium and copper are recorded on the media in the form of hydroxides of palladium (II) and copper (II) contacting the treated media by recommerce for 2.5 hours at approximately 5 rpm with 120 ml of an aqueous solution of sodium hydroxide obtained from the 50% mass/mass of NaOH/H2O, in the amount of 120% of the required for the conversion of the palladium and copper in their hydroxides. The solution was decanted from the treated media, which is then washed with deionized water to remove chloride-IO and copper recovered to free metal by contact of the medium with ethylene (5% in nitrogen) in the gas phase at 150oC for 5 hours, or with hydrazine at room temperature for 4 hours, followed by washing with deionized water for 2 hours and dried in an oven at 150oC for 5 hours to obtain a catalyst containing a nominal amount, comprising 4 g/l Au, 7 g/l Pb and 1.9 g/l C.

This catalyst was then impregnated with 4 g COAs in 33 ml of N2O and dried in a drying plant with fluidized bed under 100oC for 1.5 hours.

Characteristics of the Pd/Au/Cu catalyst:
CO2- 8,80
Activity - 1,87
TF - 0,702
EtOAc - 0,078 p


Claims

1. Catalyst for production of vinyl acetate by reaction of ethylene, oxygen and acetic acid containing porous media, porous surfaces of which is deposited catalytically effective amounts of metallic palladium, gold and copper, and the above-mentioned catalyst was prepared in stages, including impregnation mentioned porous media, porous surfaces which contain a catalytically effective amount of pre-reduced metal palladium and copper, a solution of Aurat potassium, and restore Aurat potassium to catalytically effective amount mwenye palladium and copper, get in stages, comprising impregnating said carrier with an aqueous solution of water-soluble salts of palladium and copper fixation mentioned palladium and copper in the form of water-insoluble compounds by reaction with an appropriate alkaline compound and restore found on the media water-insoluble compounds of palladium and copper to their free metallic state.

3. The catalyst p. 2 where the above-mentioned water-soluble palladium salt is a palladium (II) tetrachloride sodium, and the aforementioned water-soluble salt of copper is a copper chloride (II).

4. The catalyst p. 1 containing from about 1 to about 10 g of palladium, from about 0.5 to about 10 grams of gold and from about 0.3 to about 5.0 g of copper per liter of catalyst, and the amount of gold is from about 10 to about 125 wt.% based on the weight of palladium.

5. The catalyst p. 1, which is obtained with the use of reagents that do not contain sodium.

6. The catalyst p. 1 containing, in addition, the acetate of an alkali metal.

7. The catalyst p. 6, where the said alkali metal acetate is a potassium acetate is present in an amount of from about 10 to about 70 g/l of catalyst.

8. The catalyst according to p. 7, where Aurat potassium probabl the ode and acetic acid, containing porous media, porous surfaces of which is deposited catalytically effective amounts of metallic palladium, gold and copper, and the above-mentioned catalyst was prepared in stages, where the first carrier is in contact with a solution of Aurat potassium recovery Aurat potassium to catalytically effective amount of metallic gold, then the catalyst containing the medium gold, is in contact with a water-soluble complexes of palladium and copper and then restore them to the condition of the metal.

10. The catalyst p. 9, which is obtained with the use of reagents that do not contain sodium.

11. The catalyst p. 9, where the catalyst contains a thin layer of Pd, AU and si on the surface of the catalyst carrier.

12. The catalyst p. 9, containing, in addition, the acetate of an alkali metal.

13. The way to obtain a catalyst for production of vinyl acetate by reaction of ethylene, oxygen and acetic acid, comprising impregnating a porous support, the porous surfaces of which contain a catalytically effective amount previously recovered palladium and copper, a solution of Aurat potassium, and restore Aurat potassium to catalytically effective amount of metallicity and copper, get in stages, comprising impregnating said carrier with an aqueous solution of water-soluble salts of palladium and copper fixation mentioned palladium and copper in the form of water-insoluble compounds by reaction with an appropriate alkaline compound, and recovering water-insoluble compounds of palladium and copper, found on the media, to their free metallic state.

15. The method according to p. 14 where the above-mentioned water-soluble palladium salt is a palladium (II) tetrachloride sodium, and water-soluble salt of copper is a copper chloride (II).

16. The method according to p. 13 where the above-mentioned porous carrier contains from about 1 to about 10 g of palladium, from about 0.5 to about 10 grams of gold and from about 0.3 to about 5.0 g of copper per liter of catalyst, and the amount of gold is from about 10 to about 125 wt.% based on the weight of palladium.

17. The method according to p. 13, where the catalyst was prepared using reagents that do not contain sodium.

18. The method according to p. 13, where the catalyst contains a thin layer of Pd, AU and si on the surface of the media.

19. The method according to p. 13, where the above-mentioned catalyst is additionally impregnated with a solution of acetate of an alkali metal.

20. The method according to p. 19, where the above-mentioned alkali metal acetate performance of the catalyst.

21. The method according to p. 20, where Aurat potassium is added simultaneously with the potassium acetate.

22. The way to obtain a catalyst for production of vinyl acetate by reaction of ethylene, oxygen and acetic acid containing porous media, porous surfaces which contain a catalytically effective amount previously recovered palladium, gold and copper, in which the first carrier is in contact with a solution of Aurat potassium recovery Aurat potassium to catalytically effective amount of metallic gold, then the catalyst containing the medium gold, is in contact with a water-soluble complexes of palladium and copper and then restore them to the condition of the metal.

23. The method according to p. 22, where the catalyst was prepared using reagents that do not contain sodium.

24. The method according to p. 22, where the catalyst contains a thin layer of Pd, AU and si on the surface of the media.

25. The method according to p. 22, where the catalyst contains, in addition, the acetate of an alkali metal.

26. The method according to p. 25, where Aurat potassium is added simultaneously with the potassium acetate.

 

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