SA96170041B1 - A catalyst for the manufacture of vinyl acetate - Google Patents

Abstract

Abstract: The invention relates to a useful catalyst for the manufacture of vinyl acetate from ethylene, acetic acid, and oxygen consisting of palladium metals, gold, and a metal from the group consisting of. zirconium rhenium and porous backing material. The catalyst is made by adsorbing water-soluble salts of minerals onto a support material, then precipitating the metal as a water-insoluble salt, and reducing the salt to the metal.

Description

. Catalyst for the manufacture of vinyl acetate Full description BACKGROUND OF THE INVENTION The present invention relates to a new catalyst useful in the reaction of 071606; oxygen; and acetic acid in the vapor state to form vinyl acetate with an ald face The present invention is directed to a catalyst new useful in the catalytic formation of vinyl acetate in which the said catalyst includes metallic palladium, gold, and an addition of at least one metal from the group consisting of zirconium s thenium deposited on a suitable porous support material. Known in this art is the possibility of producing vinyl acetate by reacting ethylene with oxygen and acetic acid in the gaseous state and in the presence of a catalyst including 0811801070 acetate 5 “ad alkali metal supported on certain carriers such as 5811108. These systems appear for a substance acceptable activity catalyst 0 in general; low tendency for products “ethyl acetate “carbon dioxide Jie” io gill and heavy ends Generally, the patents indicated for the manufacture of catalysts for commercial manufacture of vinyl acetate of ethylene < acetic acid and oxygen Describe and name various methods of precipitation of mineral components, i.e. cadmium «oad palladium etc.; To form a narrow strip of metal at the backing surface of the catalyst. 1 Several more suitable vinyl acetate catalysts and their manufacturing methods are discussed below. US Patent No. 37970917 shows the preparation of a catalyst for the preparation of unsaturated organic esters, where the catalyst consists of unsupported or supported metals of the platinum or palladium group, oxides or terminating salts, whether organic or inorganic. A supported catalyst is prepared by dissolving the metal salt or salts in; For example; cele add the support material and evaporate 0 the solvent. The noble metal is evenly distributed throughout the reinforcement bale. lad patent; The activity of the catalyst can be enhanced by adding a metal halide promoter. US Patent No. 7797607860 shows a palladium catalyst on an aluminum oxide support material which when reinforced with alkaline acetate was found to be suitable for the production of organic acetate; Especially 206181 vinyl palladium catalyst precipitates through the vo catalyst support material. There is no specific illustration in the patent on combinations of two precious metals or ony v of precious metal salt Sle using alloys. The catalyst is prepared by impregnating the support material with a solution: and precipitating the precious metal on the support material by reducing palladium. US Patent No. 76577107 shows a catalyst containing 111616 acid alkali metals. The catalyst is prepared by impregnating a carrier such as acetate 5 “aad, etc.; With an aqueous solution of aluminum phosphate “silicate R” aluminum oxide 0 and gold to palladium and gold salt and evaporation of the resulting mixture until dryness. Palladium salts are reduced to their mineral state by a reducing agent. The catalyst is then washed with water; It is impregnated with a solution of: and upon drying it is ready for use. sodium acetate suitable gold —palladium catalyst material 17774449 describes the British patent No. palladium it can be proven that the process of this patent results in the precipitation of vinyl salts To prepare 0 0066866 through the catalyst support material. The catalyst is prepared by imbibing the catalyst support material with a solution and then acetic acid in potassium acetate barium aceto-aurate palladium acetate and other additives. like gold; palladium salts it dried. It turns out that the catalyst is a salt

gold; alkaline earth metal salts; alkali metal salts supported on a material describing Japanese Patent Application Publication No. 1997700-1/178; A process for preparing the surface of an “impregnated support”. In an initial step a small amount of a reduced metal vinyl acetate catalyst (such as gold) is deposited through the porous support. This is followed by the impregnation of the required amount of a catalyst which is then deposited on the surface around the formed metal particles. The palladium catalyst is deposited as a surface layer having a thickness of about 716 or less particle ratios. It is recommended to use alkali metal palladium as an auxiliary catalyst. acetate salts © Method for preparing a metal-supported catalyst 17879777 BRITISH PATENT SPECIFICATION Transformation of (palladium “platinum) by contacting the support material with a solution of a metal compound such as the precipitate to the metallic state; the support material of the porous catalyst is impregnated with an alkaline solution of water or alcohol. It was found that the degree of penetration The mineral is for pellets of support material 7900 to YO and saturates with from of the radius of the sphere.It is recommended to use a secondary amount of material 780 The catalyst is up to Yo .sodium jy potassium acetate activated; such as oY

¢ US Patent No. 94741949 indicates the use of a catalyst where palladium is deposited on a catalyst support having a pore size of 1.4 to 1 milliliter/g and where less than 0 of the total pore volume returns to the pores Microspheres have a diameter of less than 10 ng. The usual inert materials, titanium oxide, aluminum silicates, silicates, silicic acid, czirconium oxide, and various glass are indicated as suitable reinforcement materials. For the preparation of vinyl acetate from ethylene and oxygen; The catalyst support material is impregnated with a solution of “cadmium acetate” palladium acetate, potassium acetate in acetic acid, followed by drying. US Patent 7,877,708 describes the manufacture of a vinyl acetate catalyst containing 0 liter fol ale of 7-011 palladium g/l gold on a silica support where metal salts adsorbed on the catalyst support material are deposited using an aqueous solution of sodium hydroxide in an amount equal to 1-7110 of the adsorption capacity of the support material. US Patent 460405095 describes the manufacture of a vinyl acetate catalyst in which metal salts dissolved on the support are adsorbed from a solution equal to the pore size of the support by mechanically stirring the support in a rotating vessel. When the salts are stabilized with an alkaline substance without drying, the cementing material loaded with salt. US Patent 40,897,777 states a gold palladium catalyst manufactured by a two-step impregnation and precipitation process. US Patent 775,747 describes a method for preparing a catalyst commonly called pore size impregnation. The patent indicates a vinyl acetate catalyst providing an inner band of gold palladium alloy deposited on a catalyst support. The preparation of the catalyst is demonstrated by simultaneously or sequentially treating the support of the catalyst; with or without intermediate drying; With a solution of palladium salts and gold and a solution that contains compounds capable of reacting on a material supporting the catalyst with gold palladium salts to form palladium and gold compounds that are insoluble in water and then convert palladium and gold compounds that are insoluble in water into precious metals vo by treatment with reducing agents; Remove water soluble compounds by washing. Alkali metal carboxylate is recommended; acetate Da alkali; on the catalyst so that the catalyst after drying contains from 1 to 007 percent by weight of alkali metal carboxylate. In all examples; Ony o gold and palladium solution in which the catalyst support material is treated sequentially with a solution of precipitation compounds that the catalyst dried between each successive treatment. In pore size impregnation, the quantity of the solution containing a salt of the precious metal is approximately equal to the pore volume of the porous support material. cpalladium 5 This patent lists other metals that can co-precipitate with gold, including copper. however; There is no indication in the statement on an example of how material 0 works, whether for a celal-work-rate catalyst that contains copper as a third type of metal, or that it preferably has or has a tendency toward ethyl acetate, carbon dioxide, or other impurities. It appears that vinyl acetate The inventors are only guessing at the possibility of the presence of any of the 16 or more metals shown in any concentration in the final catalyst. copper vinyl acetate and oxygen to form steam from ethylene acetic acid as a reducing metal component. however; These catalysts do not contain any gold component. That includes

U.S.A. 3759839: U.S. 3641121; U.S.A. 3671576; French Patents 1566972 and 1583899;

Japanese Patent Application (KOKOKU) 54-8638; Japan 46033013 (Chemical

Abstracts 76(8):34719a; Japan 46032644 (Chemical Abstracts 76(8): 34718z; and Vo.

Revista de Chemie Vol. 26, No. 9, pages 719-723 (1975). Several new patents were issued directed at improved methods and the resulting product. Examples directed to new methods 271 and 885/8; 57,779,701 These patents are US patent and palladium gold for the manufacture of catalysts containing a useful material formed by patent (OY) 4808 pursuant to US Patent YL US 777573467 Where minerals combine as salts thereof and adsorb in the pores of the catalyst material by simultaneously or sequentially impregnating a catalyst support material with solutions (1) Pore size impregnation method. sodium-palladium chloride and gold aqueous palladium salts of gold insoluble in E: palladium Stabilization of precious metals on the support by precipitation of sodium hydroxide compounds of water by treating the support materials impregnated with a reactive base solution such as vo and gold on the surface of the support; (¥) washing with aqueous palladium water reacts to form hydroxides of the precious metal palladium into other hydroxides); 5 (£) anion si) chloride reduction to remove the ony ion

0 and Gold Harra Cum The improvement during the stabilization step (7) includes the use of two separate sedimentation stages, where the quantities of the reacting compound connected with the support material impregnated with salt in each stage do not exceed the quantities required to interact with the water-soluble precious metal compounds impregnated in the support material. between the two separate stabilization or sedimentation phases; The support impregnated with the 0 basic reactant solution is left for a certain period of time to allow precipitation of the water-insoluble metal compounds prior to the second stabilization stage in which an additional base reactant is added to the support. The American patent (1) 07777010 shows the simultaneous or sequential impregnation of a support material with a catalyst with aqueous solutions of palladium salts and gold such as sodium-palladium chloride (Y) cauric chloride Fixation of precious metals on the support material by precipitation of palladium compounds 0 and gold insoluble in water by immersing the impregnated support material in a reactive base solution such as sodium hydroxide aqueous, which reacts to form palladium hydroxides and gold on the surface of cael (¥) washing with water to remove the ion “UAT anion Jf ) chloride 5 (£) reduction of the precious metal hydroxides to palladium and free gold; where optimization during stabilization step (Y) includes rotation of the impregnated catalyst support while the impregnated support material is submerged in the reaction solution at least ve During the initial sedimentation period and before leaving the treated catalyst for an extended period (Agia) to continue sedimentation of palladium and water-insoluble gold compounds. US Patent ©04944197 describes a process for baking the pure catalyst in an inert atmosphere for at least 11 minutes to improve the affinity of the catalyst towards the synthesis of vinyl acetate. of precious metals among other specified criteria. According to the statement; The catalyst mainly consists of (1) a Sale support catalyst having a partial diameter of about * to about ALLY and a pore size of 0.9 to about 0.9 milliliter/g; (?) gold palladium y in a ratio of about 1.60 to 0.79 distributed in a maximum layer 1 mm thick of catalyst support particles; and (7) from about Ye to about 4.0/wt Potassium acetate Yo. As can be discerned from the above examples from prior art,” the basic method for forming a palladium- and gold-containing vinyl acetate catalyst deposited on a catalyst support material has evolved into a method that includes (1) impregnation Bale fortification with aqueous solutions of soluble palladium and gold compounds

In (Teele) the precipitation of water-insoluble palladium and gold compounds on the catalyst support material by contacting the impregnated catalyst support material with a solution of compounds capable of interacting with water-soluble palladium and gold compounds to form insoluble metal compounds for solubility” (?) washing of the catalyst treated with water to remove “8010at liberated from compounds of palladium© and gold precipitated during precipitation; 5 (£) Conversion of water-insoluble palladium and gold compounds into a free metal by treatment with a reducing agent. The final treatment usually includes (0) impregnation of the reduced catalyst with an aqueous alkali metal acetate solution 5 (1) drying of the final catalyst product European patent application 17477 discloses a catalyst for the production of alcohols and/or carboxylic acid esters 00 by hydrogenation of anhydrides or carboxylic acids This catalyst comprises an alloy of at least one cream metal of group A and at least one metal one capable of making an alloy with the noble metal of said group A. Example 01 of this patent discloses a hydrogenation catalyst comprising certain amounts of gold palladium .thenium sl General description of the invention The present invention provides a new method for producing a catalyst Useful in the manufacture of Alla vinyl acetate vapor from ethylene acetic acid and oxygen which includes three or four certain metals in certain quantities. The catalyst thus produced is new in itself; as indicated by its properties. The present invention specifically provides a method for This catalyst is as specified in the claims.The invention, Lad, relates to the use of a catalyst thus prepared to produce vinyl acetate from acetic acid 0 and oxygen. The catalyst of the invention, Mall, can be manufactured by any method of the prior art for the manufacture of catalysts useful in the manufacture of vinyl acetate by the reaction of acetic acid cethylene and oxygen. Particularly useful are the methods described in US Patents 097785747 4 $OYVEAOA or 07777170 Yo The support material for the catalyst of the present invention may be in any different geometry. For example; The backing material can be formed into pellets; opal JB, regular-shaped discs, or

A

mm. The most suitable shape is 8-1 irregular. Geometric dimensions of the backing material may be; generally within mm. eg AE; spherules with diameters in the os SH geometric limits are particularly high; Shape These reinforcing materials are generally called grains. The specific surface area of the reinforcing material varies within wide limits. For example, reinforcement materials (BET “m?”/g and especially 10-110 m 0?/gr. (measured according to 0-00) having an internal surface area © are suitable. “aluminum oxide” silica on support materials Can be used including XB being the preferred support material. Silica or a mineral crystalline ore. Aluminum silicates The active metal catalyst can be prepared by any of the methods described above to prepare a material into a salt mixture of rhenium and/or zirconium Cua gold palladium metal salts are added as a catalyst 0 rhenium y “palladium the metal used to impregnate the catalyst support material. Gold salts” in an aqueous solution adsorbed in the pores of the support material described in the previous art by the method of zirconium and / or pore size impregnation; metal precipitation-treated supports are stabilized in water-insoluble compounds or ethylene; metal salts are reduced by treatment with a reducing agent; for example hydrazine 0 in one of the catalyst preparation methods of the invention Dissolve adequate amounts of soluble in water in a sufficient quantity of Zirconium i and/or salts of the pore size of the porous support material. IVY em water to yield a solution equivalent to approximately palladium examples. IDnitrate and sodium palladium (Il)chloride (11) are suitable for water solubility; While p 2101710 (111) (0110110) palladium can be used on 0 compounds for solubility in the alkali metal ALE from that as gold compounds ~ Md tetrachloroauric (Ill) acid or available sodium palladium (IT) chloride and tetrachloroauric(llll) acid in water. Zirconium nitrate “zirconium sulfate” is generally preferred because of its high solubility in water. For use as a soluble salt of the invention 8001077 perrhenate. ve also contained in the invention rhenium(III)chloride or “rhenium(VIDheptoxide) although

current VE. Typically, the quantities of these used compounds are such that they provide about? to about ony q about de g/l gold; And from about A from about 1 to about “palladium g/l” as a final catalyst. Accordingly; A to about 1 and about zirconium ? Gram/L of IV pan The amount of gold present in the catalyst is about 10 to

Bala The solution is adsorbed onto the support material; backing material is dried; The minerals are stabilized by immersing the palladium 11 hours in order to make the salts of the metal 11 the fortification in an aqueous alkaline solution of sufficient concentration for a period of not less than about 0 insoluble in water. Alternatively; The stabilization step may be performed by immersing the cured support material in sufficient volume of stabilizing solution to cover the total volume of the support material and circulating the support material as in, for example, and this method is incorporated herein by reference. (OYYYOVY method described in the US patent pursuant to For this reference, impregnated supports are immersed in an alkaline solution and stirred or swirled in it during the initial 0 oxides stages of precipitation of water-insoluble precious metal compounds as in and 170:0<1085. Supports must be continuously swirled or stirred in the stabilizing solution Alkali for at least Continue curing (Say about half an hour at initial curing preferably for at least one hour. Spin-immersion for up to hours. Cured supports may be left in the fixing solution to ensure complete sedimentation of the unstable precious metal compounds Soluble in water. ve support given Sale Any type of rotation, stirring, or similar device can be used that preserves movement because it is not important to use a specific device. What is important, however, is the range of movement. Thus, the movement must be Sufficient so that all surfaces of the support materials impregnated with the alkaline fixing solution come into contact evenly. The movement should not be so violent that actual scraping of the insoluble precious metal compounds and insoluble compounds occurs from the surface of the support material. Generally the range should be rpm and possibly higher given the support material 10 to 100 rpm for the particular item used and the amount of precious metal deposited on the support material. The number of revolutions per minute used varies and also depends on the device used; the size and shape of the backing material; The type of support material, but it must be included in the range specified above. While a small amount (GE) of abrasive metallic acids can occur; It should not reach the actual scraping of the soluble compounds from the surface of the support material ga vo to an unacceptable degree.

0 A fixing solution is a solution that includes an alkaline solution; For example; An aqueous solution containing alkali metal hydroxides li bicarbonate and/or alkali metal carbonate. It is particularly preferred to use aqueous solutions of sodium hydroxide or potassium hydroxide following the sedimentation or stabilization step; The support material is washed for example with distilled water to remove cchlorides Jia canions which are still 0 present on the support material and liberated from the initial impregnation solution by the precipitation process. Washing continues until all the “buffers” have been removed from the backing material. No more than about 0001 ppm anion should remain on the catalyst. to ensure substantially the complete removal of slaniondl as the chloride ion from the catalyst; Washing yield can be tested with nitrate “©581197. The catalyst is then dried at temperatures not exceeding about 100°C under an inert atmosphere such as continuous air flow or 0 nitrogen. The washed and stabilized material is then treated with a reducing agent to convert the metal salts and compounds present into a metallic form. Reduction can be done in the case BLY for example; with hydrazine hydrate mani 0 in the gaseous state for example; With hydrogen or ¢hydrocarbons on .ethylene “Jill Jw. If reduction is carried out with hydrazine hydrate solution 0, it is preferable to carry out the reaction at a normal temperature. When the reaction is carried out in the gas state it is useful (of ja) to react at an elevated temperature; For example; At -001 0 C in the reducing state with 0371606. It is appropriate to use the reducing agent in excess so as to make sure that all the salts and compounds of the metal are converted to the metallic form. In another useful method for preparing an improved catalyst of the present invention; A suitable catalyst support material © is first impregnated with an aqueous solution containing cand epalladium compounds and either rhenium zirconium soluble in water. Separate solutions of gold palladium compounds may also be used sequentially; and either or both czirconium y thenium But this method is less convenient. The volume of solution used to impregnate the support material with the minerals is important. for effective sedimentation; The volume of the impregnation solution should be from 99 to 71009 of the absorbent energy of the catalyst ve support material, preferably JAA after the support material was impregnated with “cand palladium” compounds and whether or both zirconium rhenium soluble water soluble; The impregnated support materials are dried prior to fixing the “palladium ony” compounds

: 11 for solubility in water on ALE as compounds other than rhenium zirconium gold; Either or both reinforcement. The stabilization step is divided into at least two separate stages of treatment with an alkaline stabilizing solution. in each separate installation process; The amount of the alkali reacting compound shall not be more than equal to the gram molecular quantity required to react with all the metal compound on the support as a water soluble compound. It is better; The amount of reactant used in each stabilization phase is less than the gram-molecular amount required to react with each water-soluble metal complex. The first stabilization stage is carried out by impregnating the impregnated support with an alkaline stabilizing solution in an amount equal to about the dry adsorption capacity of the support. The amount of the alkali compound of the anion soluble metal salt present in the solution should be such that the ratio of alkali metal to mole and the volume is equal to the absorbent energy of the substance of about 1 AVY of water from about 0 backing dry. The fixing solution is simply poured onto the impregnated support and the support is left for an hour or more while it sets. The second stabilization stage is carried out by adding approximately approx. partially dried un-stabilized YE grains to a second volume of aqueous stabilizing solution. In this solution you should be mol.vid to about 0:0. of metal salt of about anion to alkali ratio The volume of the solution should cover the grains. It is better; The total amount of alkali metal should be within 1 mol for the combined stabilization step. following treatment (V0), to about 0.1:1 of about aniond) in the first stabilization stage; The cured supports are left for a period of time sufficient to allow precipitation of insoluble metal compounds. The time period for the first stabilization step varies but typically ranges from hours before the support material is treated again with a second volume of stabilizing solution A of about ? to about : alkali.© after treatment in the second stabilization stage; The cured reinforcement materials are left again for at least two hours. An additional 11 hours is preferred; at least ; hours and may be left to complete sedimentation until about, the treatment in the second stabilization stage is equal to the first stage where the dry and partially stabilized support materials impregnate the cured with the stabilizing solution at the desired alkaline concentration. Total volume to cover the volume of the support. AS of the solution vo Impregnation of the support material in the second stabilization stage by a process called rotary immersion (Say Ay method) In this process, the catalysts are immersed in the stabilizer .2077797010 patented. American invention ony

A once in the alkaline fixing solution and stirred or rotated in it during the initial stages of precipitation of the water-insoluble metal compounds. The stirring of the catalysts in the alkaline fixing solution should continue for at least half an hour at the initial treatment and; Preferably at least one hour. Rotary immersion treatment may continue until; 6 hours before curing supports are left in the stabilizing solution to ensure complete sedimentation of the water-insoluble metal compounds. as described above; Any type of spinning or flipping device can be used as the specific lead used is not important. the important; however; is the range of rotational motion. so; The rotation shall be sufficient so that all surfaces of the support materials impregnated with the alkaline fixing solution are evenly contacted. The rotation shall not be so vigorous as to actually abrasive the insoluble metal compounds such that the insoluble compounds are scraped off the surface of the support material. Generally the rotation range should be about 1 to 10 revolutions per minute and possibly lef lad more than that depending on the particular support material used and the amount of metal deposited on the support material. The number of revolutions per minute used varies and also depends on the machine used; the size and shape of the backing material; Backing Material Type » Metal Loads; etc; But it must be entered into the specified range ole so that while abrasion occurs in a small amount; vs. does not reach the actual scraping of insoluble compounds from the surface of the support material to an unacceptable degree. The fixed beads are then reduced in a stream of ethylene gas or in a solution of hydrazine hydrate by a method well known in the art. Depending on the intended use of the catalyst prepared in this way; Traditional additions can also be provided. so. For example; It is useful to add alkali metal acetate when using the catalyst © in preparing unsaturated esters from colefing oxygen and organic acids. In this case; For example; The catalyst can be impregnated; for this purpose; With an aqueous solution of potassium acetate and then dried. The catalysts according to the invention can be used with special distinction in the preparation of vinyl acetate from Ad-al-Rata. Oxygen and 8010 acetic in Ala gas. For this purpose it is particularly suitable Ye catalysts according to the invention containing silica as the support material and additives of alkali metal acetate. In the aforementioned preparation of acetate 1071 these catalysts are also characterized by high activity, selectivity and long life. ony

VY

1 example spherical "Sud Chemie" g; Provided by You silica catalyst support material, a gram of an aqueous solution of YE, a milliliter of an aqueous solution containing AS, mm, impregnated with, 1,” and a diameter of 1.70 grams, palladium contains 718, 40 sodium palladium chloride ions contains sodium tetrachloroaurate 1 g aqueous solution of ©, 10 and rhenium heptoxide 0 gold ions. The impregnated support material is dried in hot air at a temperature of 7 ml AS aqueous solution not exceeding 100 °C. The treated and dried support material is impregnated with by soaking the grains in the solution. The volume of sodium hydroxide solution contains 1.776 grams equal to the adsorption energy of the dry support material in the first stabilization stage. after sodium hydroxide first stage; The grains leave the base-processing for a while; hours and then pour into a solution of 0 (NaOH mL aqueous solution containing 1.54 g You) sodium hydroxide an additional hour. after installation; Article 11 washes the second treatment; The treated material leaves the base for about to an acceptable level which is mostly chloride. Treat the base well with distilled water to remove ions * “cm”/min for about 00. The water flow rate is about 0 ppm chloride. hours The catalyst is dried by inducing a continuous stream of nitrogen at a temperature not exceeding 70 ve in ethylene 70 ºC The dry catalyst is reduced with a reducing gas containing 00 nitrogen at 100 ºC The reducing gas is passed over the catalyst for © hours Marg 01 at atmospheric pressure The reducing catalyst is impregnated with an aqueous solution containing at a volume of solution equal to the dry adsorption energy of the support potassium acetate is dried 101°C the catalyst is dried at a temperature of © example ? Instead of zirconium sulfate using 1.54 grams, the example method is repeated.

NaOH grams 7.7 4 Jl In each of the two stabilization steps, a rhenium heptoxide solution is used, for example? an aqueous solution containing; 4.7 grams of aqueous solution Ao 5, 10 grams and zirconium sulfate 1.04 grams “palladium” containing 718.50 oy ions

\¢€ An aqueous solution of sodium tetrachloroaurate contains 770.07 gold ions. Precipitation is achieved by adding YAY milliliters of an equivalent aqueous sodium hydroxide solution to 7171 pure equivalents required to convert the metal salts into their hydroxides. The flask is rotated directly in an evaporator-rotator (without vacuum) at approximately rpm and the rotation continues for two and a half hours. after two and a half hours; The rotation is stopped and the VT alkaline treated supports are left for an additional hour to ensure maximum precipitation of the metal hydroxides ie non-ALE for solubility. The flask is filtered and the alkali treated material is washed with distilled water to remove the chloride ions. A water flow rate of about 100 cm per minute is used for about ½ hours. All catalysts are reduced with an aqueous solution of hydrazine hydrate (17/ plus) at ambient room temperature for ; hours. The grains were washed and dried for 1 hour at 100°C. The reduced catalyst was impregnated with an aqueous solution containing 10 grams of potassium acetate at a volume of solution equal to the adsorption capacity of the dry support and the catalyst was dried.

Ch

Claims (1)

yo protection elements “acetic acid from vinyl acetate with vapor Ala to prepare a useful catalyst for the manufacture of the qt-1 0 method and oxygen, which consists of a porous support material containing minerals deposited on it ethylene 7 g / liter A to Approximately 1 cpalladivm g/L 1 contains about ? to “zirconium” gold and at least one metal consisting of about 5 to about ; g / liter The mentioned method includes: rhenium g / liter drinks A to about 1 and from about 1 ° of water solubility of the aforementioned minerals; Converting the said ALE support material compounds with water soluble 1 compounds ALE said water soluble metals into non-v metal compounds by immersing said impregnated support material in a fixing solution containing a compound reacted with 4 soluble compounds water soluble mentioned for precipitation; on said backing material; a Compounds of said water-insoluble metals and while said impregnated support is immersed in 1 said fixing solution said said impregnated support is stirred therein for sufficient time to evenly coat 11 support impregnated with the fixing solution; the completion of the precipitation of the aforementioned water-insoluble compounds 1; Washing the aforementioned support material and reducing the insoluble metal compounds Vy in the aforementioned water to form free metals on the aforementioned support material. kl -Y 1 45 006000 of claim 1 wherein the catalyst consists of a porous support material containing Y with minerals deposited on it comprising from about 7 to about VE g/L palladium of 1 and about 1 to A g/l gold and from about © to about ; g/l zirconium 01 *- The method (method Claim 1) where the catalyst consists of a porous support material containing Y with minerals deposited on it that include from about ? to about VE g/l palladium of about Y 1 to A grams/liter of gold and about 1 to A grams/liter of thenium 0 ?- method (method Claim 1) where the catalyst consists of a porous cement bale containing minerals deposited on it that include from about * to about VE g/l palladium of 3 about 1 to A g/L gold and from about © to about g/L zirconium and from ¢ about 1 to A g/L dts1. “acetic acid from vinyl acetate as steam to prepare a catalyst useful in the manufacture of method © - method 1 and oxygen, which consists of a porous support material containing minerals deposited on it ethylene l ony It includes about * to VE g/L palladium of about 1 to about A g/L of gold and at least one metal of about 1.9 to about ; g/l zirconium ° and from about 1 to about A g/l rhenium and the mentioned method includes: 1 contact of the aforementioned support material with at least one of the aforementioned water-soluble metal compounds v to impregnate the water-soluble compound mentioned on the backing material; Conversion of said water-soluble metal compound(s) A into water-insoluble metal compound(s) 1 by contacting the support impregnating material mentioned in the Olsey stabilization step with 01 solution containing a compound reacted with the compound soluble in said water to precipitate on “1” said support material the said water-insoluble mineral compound contact of said first imbibed and stabilized ay support material with at least one of the said water-insoluble compounds of said minerals to impregnate the soluble compound(s) Soluble in water: ¥ the aforementioned on cael material converting the aforementioned water soluble compound(s) of the aforementioned minerals into a water-insoluble mineral compound(s) by ve contacting the aforementioned impregnated support material in a second stabilization step with a second solution containing VY compound reacted with said second water soluble compound to precipitate on said support material VA said second water insoluble metal compound; and after this reduction of said water insoluble metal compounds to form precious metals Free on backing material Y. mentioned. 1>- The method of the protection element © where the catalyst consists of a porous support material containing Y with minerals deposited on it that include from about IY about VE g/l cpalladium of about Y 1 to A g/l of gold and from about 1.9 to about ; g/l zirconium 0 7- The method of protection element © where the catalyst consists of a porous support material containing minerals deposited on it that include from about JY about VE g/l palladium of 1 Jar to A grams/liter of gold; And from about 1 to A grams / liter of thenium 0 +- the method of the protection element © where the catalyst consists of a porous cement bale containing 0 minerals deposited on it, including about 1 to about VE g/l 08118000 from ely and Y is about 1 to +4 g/l gold and from about 1.5 to about ; g/l zirconium and from ¢ about 1 to A g/l thenium 00 4- Using the catalyst prepared in this way from any previous protection element in the production of vinyl acetate 7 from ethylene cacetic acid And oxygen.