MXPA99010221A - Process for preparing carboxylic acid salts and catalysts useful in such process - Google Patents

Abstract

Supported catalyst useful in the preparation of carboxylic acid salts, said catalyst comprising;an alkali resistant support, a plurality of metal particles selected from the group consisting of osmium, iridium and rhodium and a coating of a catalytically active metal selected from the group of copper, cobalt, nickel, cadmium or mixtures thereof.

Description

PROCEDURE FOR PREPARING CARBOXYLIC ACID SALTS, AND CATALYSTS USEFUL IN SUCH PROCEDURE BACKGROUND OF THE INVENTION This invention relates to the preparation of carboxylic acid salts and, more particularly, relates to a method for preparing carboxylic acid salts by reaction of primary alcohols with a hydroxide base, in the presence of a novel catalyst. The invention also relates to the preparation of the catalyst and its compositions. The carboxylic acid salts are useful in various applications. The salts can be neutralized to the corresponding acids, which are also useful in numerous applications, such as a material for pharmaceuticals, agricultural chemicals, pesticides and the like, or their precursors. Many of these carboxylic acids can be obtained commercially in large quantities. U.S. Patent 4,782,183, to Goto and co-inventors, discloses a method for making aminocarboxylic acid salts, comprising contacting an aminoalcohol with an alkali metal hydroxide, in the presence of a Raney copper catalyst or a copper catalyst supported on an oxide of zirconium. U.S. Patent 4,810,426, Fields and co-inventors, describes a process for producing N-phosphonomethylglycine by oxidizing N- phosphonomethylethanolamine or its internal cyclic ester, with an excess of an aqueous alkali, and in the presence of a copper catalyst; and subsequently heating to a temperature between 200 ° C and 300 ° C. The resulting salt is neutralized with an acid to produce the desired N-phosphonomethylglycine. U.S. Patent 5,292,936, Franczyk, describes an improved process for preparing an aminocarboxylic acid salt. According to the process an aqueous solution of an aminoalcohol is contacted with an alkali metal hydroxide, in the presence of an effective amount of Raney copper catalyst having from about 50 parts per million to 10,000 parts per million of a selected element of the group consisting of chromium, titanium, niobium, tantalum, zirconium, vanadium, molybdenum, manganese, tungsten, cobalt, nickel and their mixtures. While satisfactory results are achieved by the prior art methods for converting an alcohol to a carboxylate, using a copper catalyst, or even a Raney copper catalyst, it has now been discovered, in accordance with the teachings herein. invention, that the novel catalysts of the present invention can be used to convert an alcohol to an acid salt in a shorter period of time than other copper catalysts, including Raney copper catalysts, which results in significant savings of capital and operating costs when such reactions are practiced on a commercial scale.

The journal article "Dependence of Selectivity on the Preparation Method of Copper /" - Alumina Catalysts in the Dehydrogenation of Cyclohexanol ", (" Dependence of the selectivity in the method of preparation of copper catalysts / "- alumina, in the dehydrogenation of cyclohexanol ) by Hsin-Fu-Chang and co-authors, Applied Catalysis A: General, 103 (1993) 233-242, discloses a method of electroless coating, a precipitation method and an impregnation method, in the preparation of eleven copper catalysts /"-alumina. The effects of the preparation method on the dehydrogenation reaction of cyclohexanol was investigated. The results showed that the dehydrogenation activity increased as the copper load increased to a certain limit, and then declined with additional copper charges.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a new and useful method for making a carboxylic acid salt, comprising contacting a primary alcohol, in the presence of water, with a strong hydroxide base, such as an alkali metal hydroxide, a metal hydroxide alkaline earth metal, a tetraalkylammonium hydroxide and the like, in the presence of an effective amount of a catalyst suspended in water, and comprising a hydroxide-resistant support, from about 0.05% by weight to about 10% by weight, with based on the total weight of the catalyst, of an anchor metal finely divided, selected from the group consisting of osmium, iridium, radium and their mixtures. The anchoring metal is deposited or imbedded on the support, between about 1% by weight and about 50% by weight, based on the total weight of the catalyst, of a metal selected from the group of: copper, cobalt, nickel, cadmium and its mixtures, in an elementary state, which has been metallized without electrodes, in at least some of the particles of the anchor metal. It should be understood that the term "metallized or electroless application", as used herein, means the chemical deposition of an adherent metal coating on a suitable substrate, in the presence of an externally applied electrical source. The invention also relates to a catalyst useful in the preparation of carboxylic acid salts, comprising a hydroxid resistant support, such as carbon, preferably activated carbon; about 0.05 wt% to 10 wt%, based on the total weight of the catalyst, of an anchor metal in the form of particles, selected from the group of metals: osmium, iridium, radium and their mixtures, deposited on or embedded in the support, and between about 1% by weight and about 50% by weight, based on the total weight of the catalyst, of an element selected from the group of: copper, cobalt, nickel, cadmium and their mixtures, applied without electrodes in at least some of the anchor metal particles. The catalyst is prepared by a method comprising: depositing about 1 weight percent to 50 weight percent, based on the total weight of the catalyst, of an element selected from the group of: copper, cobalt, nickel, cadmium and mixtures thereof, on a hydroxides resistant support, having from about 0.05% by weight to about 10% by weight, of an anchor metal, selected from the group of: osmium , iridium, radio and their mixtures. Also according to the present invention there is provided a novel and useful method for preparing a catalyst, applying without electrodes an element selected from the group comprising: copper, cobalt, nickel, cadmium and their mixtures. The method comprises the steps of mixing together, in water, a source of water-soluble ions, said metallizing metal or application; a suitable complexing agent, and an alkali resistant support, which carries particles embedded in an anchoring metal, and then slowly adding a reducing agent to the resulting mixture, to reduce said ions to the elemental form; whereby the metal resulting from the reduction is applied or metallized without electrodes on at least some of the non-embedded surfaces of the anchoring metal.

DESCRIPTION OF THE DRAWINGS In the attached drawings: Figure 1 is a sectional representation of the novel catalyst of the invention. Reference number 1 denotes an alkali resistant support, on which the particles of an anchor metal 2 are partially embedded. The non-embedded surface of the metal The anchor is coated with a metallisation 3 without electrode, of a non-precious metal, catalytically active, in the elemental state. Figure 2 illustrates an anchor metal particle 2, when it has not been metallized without an electrode. A non-precious metal particle that is fixed to the support, but that has not been metallized or applied to the anchoring metal, is denoted by the number 4.

DETAILED DESCRIPTION OF THE INVENTION The primary alcohols which are useful as starting materials in the process of the present invention can be aliphatic, cyclic or aromatic, monohydric or hydrophilic compounds, which react with a strong base to form a carboxylate. It is necessary that the alcohol and the resulting carboxylate be stable in a strongly basic solution; and that the alcohol is at least somewhat soluble in water. Suitable primary monohydric alcohols include aliphatic alcohols which may be branched alcohols, straight chain, or cyclic and aromatic, such as benzyl alcohol, and may be substituted with various non-impeding groups, provided that the substituent groups do not adversely react with a strong base, the hydroxide resistant support or the catalyst, at the temperatures and pressure used for the conversion of the alcohol to the acid. Suitable aliphatic alcohols include: ethanol, propanol, butanol, pentanol and the like.

The aminoalcohols represented by the formula: they are also useful as starting materials in the present process, wherein n is an integer from 2 to 10 or more and m is at least 1, and may be up to 50 or more. When R1 and R2 are both hydrogen and n is 2, the aminoalcohol is monoethanolamine. When one of R1 and R2 is -CH2CH2OH or -CH2COOH and the other group R is hydrogen and n is 2, the resulting product of the aminoalcohol would be an iminodiacetate salt. When both R1 and R2 are -CH2CH2OH or -CH2COOH, the resulting product of the aminoalcohol would be a nitrilotriacetate salt. Specific aminoalcohols include, for example: monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-ethylethanol-amino, N-isopropylethanolamine, N-butylethanolamine, N-nonylethylamine, N- (2-aminoethyl) ethanolamine, N- (3- aminopropyl) -ethanolamine,?,? - dimethylethanolamine, N, N-diethylethanolamine,?,? -dibutylethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-propyldiethanolamine, N-butyldiethanolamine, N-methyl-N- (3-aminopropyl) Ethanolamine and 3-aminopropanol. In the above formula, R1 and / or R2 may also be an alkyl group having from 1 to 6 carbon atoms; for example: methyl, ethyl, propyl, isopropyl, butyl, isobutyl and the like. By the practice of the present invention, corresponding amino acid salts are provided, with these alkyl groups, which are useful in numerous applications. R1 or R2 may also be a phosphonomethyl group, such that the starting amino acid may be N-phosphonomethylethanolamine, and the resulting amino acid salt may be the N-phosphonomethyl-glycine salt. When one of R1 or R2 is phosphonomethyl and the other is -CH2CH2OH, the resulting amino acid salt is the salt of N-phosphonomethyiminodiacetic acid, which can be converted to N-phosphonomethylglycine, by various techniques known to those skilled in the art. When one of R1 or R2 is phosphonomethyl and the other is the lower alkyl group, the resulting amino acid salt is N-aikyl N-phosphonomethylglycinate, which can be converted to N-phosphonomethylglycine by the teaching of Miller's U.S. Patent 5,068,404. and Balthazor. Another aspect of the present invention is the use of the catalyst of the present invention, wherein the amino alcohol to be dehydrogenated to the corresponding carboxylic acid salt is a compound having the formula: OR HO-P-CH2-N-CH2CH2OH OH i CH2R1 wherein Ri is aryl of 4 to 7 carbon atoms, preferably phenyl, and the resulting carboxylic acid salt is an alkali metal salt of N-phosphonomethyl Igl icine. The amount of catalyst to be used to convert the alcohol to the corresponding acid may be between about 1 weight percent and about 70 weight percent, preferably 1 to 40 weight percent, based on the amount of the starting alcohol. It has been found that the catalyst of the present invention can generally be used repeatedly in the reaction, for a greater number of times than a conventional Raney copper catalyst. Suitable hydroxide bases for use in the process of the present invention include the alkali metal hydroxides, such as magnesium hydroxide, calcium hydroxide, barium hydroxide and the like. The hydroxide base can also be a tetraalkylammonium hydroxide having up to and including 5 carbon atoms in each alkyl group, such as tetramethylammonium hydroxide, dimethyldipropylammonium hydroxide, tributylethylammonium hydroxide and the like, or other strong organic bases, such as guanidine However, alkali metal hydroxides are preferred. Suitable alkali metal hydroxides for use in the process of the present invention include: lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide and cesium hydroxide. Due to its ease of obtaining and its ease of handling, sodium hydroxide and potassium hydroxide are preferred; being especially preferred sodium hydroxide. The amount of the hydroxide base to be used is an equivalent amount, on the scale of 1.0 to 2.0 equivalents, with respect to the hydroxyl group of the alcohol to be used in the reaction, as determined after the neutralization of any acid and / or hydrolysis functional groups of any ester functional groups, of the amino alcohol starting material. The hydroxide may be in the form of flakes, powder, pellets or an aqueous solution. In the process of the present invention it is only necessary to contact the alcohol with the alkali metal hydroxide in a reaction vessel, in the presence of the catalyst of the present invention, at a temperature between about 70 ° C and 250 ° C, preferably between about 100 ° C and about 190 ° C and, more preferably, between about 40 ° C and 180 ° C. At temperatures above about 220 ° C, the catalyst generally begins to lose some selectivity. At temperatures below about 50 ° C satisfactory results can be obtained, but the reaction can be undesirably slow. Normally, although not always, a pressure above atmospheric pressure is required for the reaction to proceed at the temperatures indicated above. However, it is desirable that the reaction pressure be as low as possible to provide a sufficiently high reaction rate. In general it is necessary to exceed the minimum pressure at which the reaction proceeds in the liquid phase, preferably between about 1.96 x 10s pascais and about 2.94 x 10s pascais, from preference in the approximate scale of 4.90 x 105 pascais to approximately 1.96 x 106 pascais. The conversion of the alcohol to the corresponding acid salt proceeds with release of hydrogen, which is carefully left out of the atmosphere from the reaction vessel under pressure. The escape to the atmosphere can be monitored to determine the rate and the degree to which the reaction is complete. As is well known in the art, the metallization or application of metal without electrodes, results in the absence of an applied electric current from the outside, using an aqueous plating bath or an aqueous solution of deposition of a water soluble salt of the metal that is going to be deposited. The preferred metal is copper, which is present in the plating bath as a water-soluble salt, such as copper sulfate (cupric) and the like. Other conventional ingredients in the bath include a reducing agent, an alkali hydroxide, a complex former or chelating agent, and optionally other formulation additives, such as stabilizers, surfactants, brighteners and wetting agents, etc. The selection of what specific bath composition is to be used is based on various factors that are well known in the art. The preferred reducing agent for copper deposition is formaldehyde or another reducible substance XCOO ", where X is hydrogen for formaldehyde and CH3 for acetaldehyde For reduction without nickel electrodes, suitable reducing agents include, for example: sodium hypophosphite, sodium borohydride, dimethylaminoborane (DMAB) and hydrazine. Suitable chelating agents or suitable complexing agents include Rochelle salts (tartrates), ethylenediaminetetraacetic acid (EDTA), N-hydroxyethylethylenediaminetriacetic acid (HEEDTA), nitrilotri acetic acid (NTA), N, N, N1, N1-tetracis- (2-hydroxypropyl) -ethylenediamine (Quadrol chelator) or other substances to ensure that the metal ion is kept adequately soluble in the metal bath without electrodes. The particles of the anchor metal to be coated are embedded in the surface of an alkali-resistant support, to form a substrate. Preferred are finely divided platinum particles embedded in a carbon support. The substrate is contacted under suitably selected pressure conditions, temperature and time, for the best deposition of the chelated metal on the anchoring metal, and sometimes as resting, free metal particles, fixed to the substrate. Suitable temperatures range from the freezing point of the deposition solution to the reflux temperature. The thickness of the metallic coating is selected to give a catalytic surface. In general, the thickness of the base metal coating on the metallized metallic anchoring particles is approximately 0.3 to 500 nanometers, preferably 1 to 5 nanometers.

Surfactants can also be used in the plating bath without electrodes. Suitable surfactants are substances that are capable of lowering the surface tension of a liquid or the interfacial tension between a liquid and a solid. Said substances possess the common aspect of a water-soluble (hydrophylic) portion attached to an organic (hydrophobic) portion and include detergents and emulsifiers. The hydroxide-resistant support in the catalyst is necessary since the reaction for converting the alcohol to the corresponding acid salt is carried out in a strong basic solution. Suitable supports include: titanium oxide, zirconium oxide and carbon. Of these, coal is preferred. Still more preferred is activated carbon. The particulate anchoring metal, deposited on the hydroxide resistant support, is selected from: osmium, iridium, radium or mixtures thereof. Of them iridium is currently preferred. The amount of anchor metal to be deposited on the hydroxide-resistant support can vary from about 0.05 weight percent to about 10 weight percent, based on the total weight of the catalyst. When less than about 0.05 weight percent of anchoring metal is deposited on the hydroxide-resistant support, there is insufficient anchoring metal to be combined with copper, cobalt, nickel and / or cadmium to give a satisfactory catalyst for many reactions. On the other hand, when more than about 10 weight percent of anchoring metal is deposited on the support, based on the total weight of the catalyst, the size of the crystallite metal deposited or coated tends to increase. Larger sizes of applied elemental metal crystal sometimes lead to reduced catalytic performance. It is preferred to use from about 0.1% by weight to about 5 percent by weight, based on the total weight of the catalyst, of the anchoring metal. Suitable hydroxide-resistant supports, which contain a suitable anchoring metal, can be obtained commercially. The catalyst of the present invention is prepared by depositing from about 1 weight percent to about 50 weight percent, based on the total weight of the catalyst, of an element selected from the group consisting of copper, cobalt, nickel, cadmium and their mixtures, on a hydroxide-resistant support, having about 0.05 weight percent to about 10 weight percent of an anchor metal, preferably selected from the group consisting of osmium, iridium, rhodium and their mixtures. The amount of deposited element (ie, copper, cobalt, nickel and / or cadmium) must be sufficient to cover at least some of the embedded particles. In addition to the coated particles, there may be the presence of at least some particles of the coating or metallized metal, embedded in the support, but not adherent on the anchoring metal. X-ray photoelectron spectroscopy (XPS) is a technique that can be used to measure the relative concentration of deposited surface atoms in the catalyst. Using this technique, it has been found that, preferably in the catalysts of this invention, the atomic ratio of surface by XPS of the metal deposited on the anchoring metal is greater than 2.0, and more preferably, the atomic ratio of surface by XPS is greater than the general atomic ratio correspondent. Any number of techniques can be used to deposit the anchoring metal on the alkali resistant substrate, and to deposit the copper, cobalt, nickel and / or cadmium on the anchoring metal. However, it is preferred to use metal deposition without electrodes. As stated above, electroless metal deposition refers to the chemical deposition of an adherent metal coating on a suitable substrate in the absence of an externally applied electrical source. Regardless of the method to deposit the anchor metal on the substrate, the size of the anchor metal particles is an important parameter, as the size influences the size of the 5 copper, cobalt, nickel and / or cadmium crystals that are going to be deposited. The average crystalline size of copper, cobalt, nickel, cadmium or their mixtures must be less than approximately 500 angstroms; and in the case of copper, it is preferred that the average crystalline size be less than about 300 angstroms. Although the inventors do not wish to or adhere to any particular theory, it is believed that a uniform distribution of the anchoring metal is better to obtain high yields of the reaction; although it is not necessary to achieve fast reaction speeds.

Additionally, it is believed that it is important to have small, well-reduced, highly dispersed anchor metal particles. In practice, the substrate containing the anchoring metal is added to water and a suspension is made therein. Next, a metallizing solution, for example, a copper applicator solution, is prepared by mixing the metallizing solution in the appropriate proportions, while moderately stirring the substrate suspension and the water, at a temperature of about 0 ° C to 30 ° C. or more in an open container. The metallizing solution containing a complexing agent and a reducing agent is added to the suspension in small increments, monitoring the pH with each addition. After an appropriate time interval, the next increase in suspension is added slowly. The amount of metallizing solution depends on the desired weight percentage of the catalytic element on the catalyst anchoring metal. When the deposition of the catalytic element is complete, an essentially colorless filtrate results. The resulting aqueous solution in one embodiment of the invention comprises the following active ingredients: Copper sulfate 4.0 g / L Formaldehyde 6.0 g / L Sodium hydroxide 9.0 g / L Excess of EDTA chelator 0.06 molar The final catalyst is then filtered and washed with distilled water. Filtration is best carried out in an inert atmosphere, such as a blanket of nitrogen, to avoid exposure of the catalyst to the air. Washing the catalyst removes unreacted components, such as parts per million impurities and unreacted reducing agent, such as formaldehyde. It has been found that about 0.5 to about 1.5 weight percent alkali metal remains in the catalyst, which is usually not harmful. The catalyst should be stored in a way that avoids exposing it to oxygen, preferably keeping it under water. The invention is further illustrated, but not limited, by the following examples. As indicated above, the preferred method for preparing the catalyst of the present invention comprises the steps of first stirring or mixing together, in water, a source of water-soluble metal ions, such as copper ions; a suitable complexing agent and an alkali resistant support, which bears embedded anchor metal particles; and then slowly adding, for example, by dropwise addition, a reducing agent, such as formaldehyde, hydrazine or the like, to the stirred mixture. The metal ions are reduced to the elemental metal form and the metal resulting from the reduction is applied without electrodes, at least on some of the non-embedded surfaces of the anchoring metal. Some of the reduced metal can be deposited as metallic particles that remain free, on the support, deposited on the anchoring metal.

EXAMPLE 1 This example illustrates the preparation of a catalyst of the present invention. In a one-liter glass beaker containing an applied Teflon polymer, a five-centimeter-long magnetic stir bar on a magnetic stir plate is added 169 ml of distilled water (and 5 weight percent of Iridium on activated carbon, in the form of a powder, obtainable from Degussa Corporation, of Ridgefieid Park, NJ, USA, which corresponds to 13.37 grams, based on dry weight.In a separate liter beaker, a copper application solution, adding the following components, most of which can be obtained from MacDermid, Inc., of Waterbury, CT, USA, with agitation, in the following order: (1) 687 ml of deionized water (2) ) 90 mi MACuPlex Ultra Dep 1000B * (3) 54 ml MACuPlex Ultra Dep 1000A * (4) 18 ml MACuPlex Ultra Dep 1000D * (5) 5 ml formaldehyde 37% w / w * Products owned by MacDermid TOTAL VOLUME: 854 mi. In accordance with the MacDermid product description for product key No. 17970, the resulting aqueous solution comprises the following active ingredients: Copper sulfate 4.0 g / L Formaldehyde 6.0 g / L Sodium hydroxide 9.0 g / L Excess of chelator 0.06 molar EDTA The resulting metallizing solution is filtered and then added to the stirred suspension of 5 percent iridium on activated charcoal, adding increments of 122 milliliters every 3 minutes, at 40 ° C. The pH is monitored to verify the degree of the reaction. The time between additions is prolonged when the release of gas becomes too vigorous. After the addition of the metallizing solution is complete, the catalyst is recovered by filtration, using a 4 liter vacuum flask, a 350 ml thick glass filter funnel, and a glass dome over the top of the funnel , purged with nitrogen. After filtering, the solid material is washed with three to four 250 ml portions of deionized water.

EXAMPLE 2 This example shows another preparation of a catalyst of the present invention. To a 2 liter glass beaker, containing Teflon polymer applied, 2.5 cm long magnetic stir bar, on a magnetic stir plate, 190 ml of distilled water is added, followed by 5 weight percent osmium. on activated carbon, obtainable from Degussa Corporation, which corresponds to 16.42 g (dry weight). An aqueous copper applicator solution is prepared in a 4 liter beaker, adding the following components, with stirring: () 500 ml deionized water (2) NaKC4H 06.4H20 (tartrate [29.99 g, 0.106 mol]; stirring until dissolved. (3) 11.79 g of CuSO4.5H20 (3 g of Cu) (0.047 mol) in 400 ml of deionized water is dissolved in a separate beaker. (4) Copper solution (3) is added. to the resulting tartrate solution (2). (5) 13.60 g of NaOH (0. 7 mol) is added at 50 percent. (6) 11.35 ml (0.15 mol) of formaldehyde at 37 percent by weight. TOTAL VOLUME: 1125 ml.

The resulting metallizing solution is added to the 5 percent by weight osmium suspension on carbon, in a total of approximately twelve increments of 79 ml, each increment added separately every 2.5 minutes. The pH is monitored to verify the degree of the reaction and to delay the addition of increments in time, if and when the degassing of the solution becomes too vigorous. After the metallizing solution is added to the suspension, the catalyst is recovered by filtering as in Example 1. 0 EXAMPLE 3 Example 2 is repeated, except that components (1) to (5) are mixed together with the iridium-carbon substrate; and then the formaldehyde is added dropwise to the resulting mixture, over a period of 30 minutes.

EXAMPLE 4 This example illustrates the preparation of another catalyst of the present invention and its use. In a 4-liter glass beaker, containing the applied Teflon polymer, 5-centimeter-long magnetic stir bar, on a magnetic stirring plate, 471 ml of water is added distilled and rhodium at 3 percent by wet weight on activated carbon, which corresponds to 40.5 g of 3 percent by weight palladium on activated carbon, based on dry weight. In a separated 4 liter beaker, a copper applicator solution is prepared by adding the following components, with stirring, in the following order: (1) 1918.6 ml of deionized water (2) 251.2 ml of MACuPlex Ultra Dep 1000B ( 3) 150.73 ml of MACuPlex Ultra Dep 1000A (4) 50.24 ml of MACuPlex Ultra Dep 1000D (5) 13.96 ml of formaldehyde at 37 percent by weight. TOTAL VOLUME: 2384.8 mi. This metallizing solution is added to the suspension of 3 weight percent rhodium on activated carbon, obtainable from Engelhard Corporation of Iselin, NJ, U.A., adding increments of 200 milliliters every 2.5 minutes. The pH is monitored to verify the degree of the reaction. The time between incremental additions is prolonged when the release of gas becomes too vigorous. After the metallizing solution is added, the catalyst is recovered by filtration, using a 4 liter vacuum flask, a 500 ml thick glass filter funnel, and a glass dome over the top of the funnel purged with nitrogen. After filtering, the solid material is washed with three to four 250-milliliter portions of deionized water.

EXAMPLE 5 This example illustrates the use of the catalyst herein to convert N- (2-hydroxyethyl) aminomethylphosphonic acid to N-phosphonomethyoglycine. A mixture of 12.0 g (0.077 mol) of N- (2-hydroxyethyl) aminomethylphosphonic acid, 120 g of water, 21.7 g (0.271 mol) of sodium hydroxide is charged into a 300 ml nickel autoclave equipped with a stirrer. sodium at 50 weight percent and 12.5 g of the catalyst of example 2. The autoclave is sealed and heated at 150 ° C under pressure of 9.32 x 10s pascais, while stirring the liquid phase in the autoclave until the evolution essentially ceases of hydrogen.

EXAMPLE 6 This example illustrates the conversion of 2-oxo-3-oxazolidinylmethylphosphonic acid to N-phosphonomethylglycine, in salt form, using the catalyst herein. The procedure of Example 5 is repeated, except that N-phosphonomethyl-2-oxazoiidone, prepared by the process described in US Patent 4,547,324, is used in place of N-2- (hydroxyethyl) aminomethylphosphonic acid.

EXAMPLE 7 This example illustrates the use of the copper catalyst of Example 2 to convert 3-aminopropanol to sodium 3-aminopropium nate. A mixture consisting of 49.8 g (0.66 mol) of 3-aminopropanol, a suspension of 12 g of catalyst of Example 2 in 50 g of water, 57 g (0.7 mol) of 50 weight percent NaOH is charged and g of deionized water, in a Parr reactor, of nickel, of 300 ml, equipped with agitator, gas regulator to maintain constant back pressure and a mass flow indicator of hydrogen, Porter, which forms an interface with an IBM computer. Heating to 160 ° C induces rapid release of hydrogen.

EXAMPLE 8 This example illustrates the conversion of cinnamyl alcohol to the corresponding acid. It is charged in a 300 ml nickel autoclave, 50.0 g (0.37 mol) of cinnamyl alcohol, 34.6 g (0.43 mol) of sodium hydroxide, 12.8 g of the catalyst of example 2, suspended in 48.6 g of water, and additionally 75 g of water. The autoclave is sealed and purged with nitrogen. The autoclave is heated under pressure of 1.0 x 106 pascais at 170 ° C. After the evolution of hydrogen ceases, the reaction product is filtered and extracted the basic filtration with diethyl ether. The aqueous phase is acidified and extracted with ether. The acid and basic extracts are evaporated and analyzed.

EXAMPLE 9 This example illustrates the conversion of polytetrahydrofuran (PTHF) to the corresponding acid salt. The polytetrahydrofuran used in this example is a straight chain polymer of the formula H (OCH2CH2CH2CH2) nOH, with average molecular weight of about 250. It is charged in a 300 ml autoclave, 15 g of the catalyst prepared according to example 2; 35.0 g of 50 weight percent sodium hydroxide, 37.8 grams of polytetrahydrofuran and 61 grams of deionized water. The contents of the autoclave are heated rapidly, at a temperature between 160 and 1 0 ° C, while maintaining the pressure at 1 .03 x 106 pascais. Stirring is maintained at 800 revolutions per minute. After the evolution of hydrogen ceases, the product of the reaction is cooled to 95 ° C and removed from the autoclave. The autoclave is rinsed with about 50 ml of distilled water. The filtrate is combined with the wash water and analyzed for the dibasic acid content.

EXAMPLE 10 Example 13 is repeated, except that polyethylene glycol having an approximate molecular weight of 200 was used instead of polytetrahydrofuran. The diol is converted to the disodium salt of the corresponding dibasic acid, which has the formula: NaOOCCH2- (OCH2CH2) x-OCH2COONa.

EXAMPLE 11 In this example, N-benzyl-N-phosphonomethyl-aminoethanol is converted to the corresponding alkali metal salt of N-phosphonomethylglycine. Example 9 was repeated, except that 35 grams of N-benzyl-N-phosphonomethylaminoethanol was used in place of PTHF. Even though the invention has been described in terms of specific modalities that are given in considerable detail, it should be understood that this is done by way of illustration only, since alternative modalities and alternative operating techniques will be apparent to the experts in the field, in view of the description. For example, the copper catalyst of the present invention can be used for any number of additional reactions, other than the conversion of an alcohol to an acid, for example, hydrogenation reactions and dehydrogenation reactions, which are common to the catalysts of copper. Further, the catalysts applied without electrodes of the present invention, which are nickel, cobalt, cadmium or mixtures combined with the anchor metal, can be used for catalyst those reactions in which the metals are commonly used as catalysts. Consequently, modifications can be made without departing from the spirit of the described invention.

Claims (31)

NOVELTY OF THE INVENTION CLAIMS

1. - A supported catalyst, useful in the preparation of carboxylic acid salts; characterized in said catalyst because it comprises: (a) an alkali resistant support; (b) a plurality of metal particles, selected from a group consisting of osmium, iridium and radium, dispersed and partially embedded in the support; the non-imbibed portion of said particles having non-imbibed surfaces; said surfaces being in an elementary state; (c) a coating of a catalytically active metal, selected from the group of copper, cobalt, nickel, cadmium or a mixture thereof; said catalytically active metal being in elemental form; said coating being fixed to at least some of the embedded surfaces of said metal particles, and covering them; said coating having a catalytically active outer surface. 2 - The catalyst according to claim 1, further characterized in that the catalytically active metal is copper. 3. The catalyst according to claim 1, further characterized in that the support is titanium oxide, zirconium oxide, carbon or activated carbon. 4. - The catalyst according to claim 1, further characterized in that some particles of the catalytically active metal are embedded in the support. 5. A supported catalyst, useful in the preparation of carboxylic acid salts, characterized in said catalyst because it comprises: (a) a carbon support; (b) finely divided particles of metal selected from a group consisting of osmium, iridium and rhodium, partially embedded in a carbon support, so as to define an embedded portion and an unimpregnated portion; the non-embedded portion having an non-imbibed surface; (c) a copper coating fixed to the metal particles and covering the non-embedded surfaces of at least some of said metal particles; the metallic copper coating having an outer surface in the elementary state; the outer surface being catalytically active in the preparation of carboxylic acid salts. 6. The catalyst according to claim 5, further characterized in that the metal particles constitute between about 0.05 and about 10% by weight of the catalyst. 7. The catalyst according to claim 5, further characterized in that the catalyst has the form of a catalytically active powder. 8. The catalyst according to claim 5, further characterized in that the amount of metallic copper is between about 1 and about 50 weight percent of the catalyst. 9. - The catalyst according to claim 5, further characterized in that some discrete copper particles are embedded in the support. 10. The supported catalyst according to claim 1, further characterized in that the metal particles constitute from about 0.05 weight percent to about 10 weight percent of the supported catalyst. 11. The supported catalyst according to claim 1, further characterized in that the metal particles constitute from about 0.1 weight percent to about 5 weight percent of the supported catalyst. 12. The supported catalyst according to claim 1, further characterized in that the catalytically active metal particles constitute from about 1 to about 50 weight percent of the supported catalyst. 13. The supported catalyst according to claim 10, further characterized in that the catalytically active metal constitutes from about 1 to about 50 weight percent of the supported catalyst. 14 - The supported catalyst according to claim 11, further characterized in that the catalytically active metal constitutes from about 1 to about 50 weight percent of the supported catalyst. 15. The supported catalyst according to claim 1, further characterized in that the XPS surface atomic ratio of the catalytically active metal to the metal particles is greater than 2.0. 16. The supported catalyst according to claim 13, further characterized in that the XPS surface atomic ratio of the catalytically active XPS surface atomic ratio of the catalytically active metal to the metal particles is greater than 2.0. 17. The supported catalyst according to claim 14, further characterized in that the atomic ratio of SPS surface of the catalytically active metal to the metal particles is greater than 2.0. 18. The supported catalyst according to claim 1, further characterized in that the XPS surface atomic ratio of the catalytically active metal to the metal particles is greater than the corresponding general atomic ratio. 19. The supported catalyst according to claim 13, further characterized in that the XPS surface atomic ratio of the catalytically active metal to the metal particles is greater than the corresponding general atomic ratio. 20. The supported catalyst according to claim 14, further characterized in that the atomic ratio of surface

XPS of the catalytically active metal to the metal particles is greater than the corresponding general atomic ratio. 21. The catalyst supported according to claim 1, further characterized in that the average crystallite size of the catalytically active metal is less than about 500 angstroms. 22. The supported catalyst according to claim 5, further characterized in that the average copper crystallite size is less than about 300 angstroms. 23. The catalyst supported according to claim 13, further characterized in that the average crystallite size of the catalytically active metal is less than 500 angstroms. 24. The supported catalyst according to claim 14, further characterized in that the catalytically active metal is copper and the average crystallite size of copper is less than about 300 angstroms. 25. The supported catalyst according to claim 20, further characterized in that the catalytically active metal is copper and the average crystallite size of copper is less than about 300 angstroms. 26. The catalyst supported according to claim 1, further characterized in that the coating defines a layer and the thickness of the layer is from about 0.3 to 500 nanometers. 27. The catalyst supported according to claim 1, further characterized in that the coating defines a layer and the thickness of the layer is from 1 to 5 nanometers. 28. The supported catalyst according to claim 13, further characterized in that the coating defines a layer and the thickness of the layer is from about 0.3 to 500 nanometers. 29. - The supported catalyst according to claim 13, further characterized in that the coating defines a layer and the thickness of the layer is approximately 1 to 5 nanometers. 30. The catalyst supported according to claim 14, further characterized in that the coating defines a layer and the thickness of the layer is from about 0.3 to 500 nanometers. 31. - The supported catalyst according to claim 14, further characterized in that the coating defines a layer and the thickness of the layer is approximately 1 to 5 nanometers. 32. The supported catalyst according to claim 20, further characterized in that the coating defines a layer and the thickness of the layer is approximately 1 to 5 nanometers. 33. The catalyst supported according to claim 1, further characterized in that the catalytically active outer surface is free of an alloy of the metal particles with the catalytically active metal.

3. 4 - . 34 - The supported catalyst according to claim 5, further characterized in that the catalytically active outer surface is free of an alloy of the metal with the catalytically active metal. The catalyst supported according to claim 32, further characterized in that the catalytically active outer surface is free of an alloy of the metal particles with the catalytically active metal. 36.- A supported catalyst, useful in the preparation of carboxylic acid salts; characterized in said catalyst because it consists essentially of: (a) an alkali resistant support; (b) a plurality of metal particles, selected from the group consisting of osmium, iridium and rhodium, dispersed and partially embedded in said support; the non-embedded portions of said particles have non-imbibed surfaces; said surfaces being in elementary form; (c) a coating of a base metal, selected from the group of copper, cobalt, nickel, cadmium, or mixtures thereof; said base metal being in elemental form; the coating being fixed to at least some of the non-imbibed surfaces of the particles of the noble metal, and covering them; said coating having a catalytically active outer surface.