Patent GB-281307-A (GB)
Title: Catalytic oxidation of organic compounds
IPC: C07D307/89
Filed: 1927-11-24
Abstract: 281,307. Selden Co., (Assignees of Jaeger, A. 0.). Nov. 24, 1926, [Convention date]. Oxygenated and dehydrogenated organic compounds.-For the catalytic oxidation of dehydrogenation of organic compounds, preferably in the vapour phase, contact masses are employed which contain at least one two-component zeolite, i.e. a zeolite obtained by the reaction silicate with one or more metallates or one or more metal salts. The active element or elements in the contact mass, together, it may be, with promoting or stabilizing elements, may be chemically combined in the zeolite molecule in one or more of four ways. (1) The zeolite may be so prepared that the non-exchangeable portion comprises silica and one or more metal oxides acting catalytically &c. in the process, and in this connection reference is made to the oxides of copper, silver, gold, bismuth, beryllium, zinc, cadmium, aluminium, the rare earths, titanium. zirconium, tin. lead, thorium, niobium, antimony, tantalum, chromium, molybdenum, tungsten, uranium, manganese, iron, nickel, cobalt, osmium, and arsenic and particularly to the oxides of vanadium which, in common with other metals among those mentioned, may be introduced in more than one stage of oxidation. (2). The siliceous portion of the zeolite molecule may be replaced in part by other acid oxides, in which connection reference is made to the acid oxides of phosphorus, sulphur, tin, titanium, tungsten, chromium, niobium, tantalum, uranium, molybdenum, arsenic, antimony, and vanadium. (3) Suitable components may be introduced into the molecule by base-exchange, in which connection reference is made to lithium, sodium, potassium, ammonium, rubidium, caesium, copper, silver, gold, beryllium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, aluminium, thallium, titanium, zirconium, thorium, tin, antimony, bismuth, vanadium, chromium, uranium, manganese, cobalt, iron, palladium, and platinum. (4) The finished zeolites mav be caused to react with certain anions to form bodies resembling salts and in this connection reference is made to anions corresponding to the acid oxides of vanadium, tungsten, uranium, chromium, molybdenum, manganese, tantalum, niobium, arsenic, antimony, bismuth, sulphur, selenium, tellurium, platinum, boron, phosphorus, and chlorine; more complex anions, such as those of ferro-, ferri-, and other metallo-cyanides, sulphocyanides, and ammonium complexes also mav be caused to react with the zeolites. Components promoting secondary reactions, such as dehydration and decarboxylation, may be included in the contact masses. The zeolites mav be made in the presence of or mixed with other materials such as non-alkaline compounds of alkali-forming metals, substances rich in silica, metal powders, metal oxides, and salts such as tungstates, vanadates, chromates, uranates, manganates, cerates, and molybdates. Such additions may be diluents, stabilizers, and / or catalysts, and in the last event the zeolite may he itself inert. The finished zeolites may also be coated on to massive carriers, such as metal fragments. It is preferred so to prepare or treat the zeolites that they are or become acid ; for example, they may be prepared from solutions which are not strongly alkaline, or treated with acids to form the salt-like bodies mentioned above, or treated with gases such as sulphur di- or tri-oxide, halogens, or nitrogen oxides at a temperature of 400-500‹C. The porosity of the contact masses may be improved by the incorporation of soluble, volatile, or combustible fillers, which are afterwards removed, and their mechanical strength may be increased by washing with a dilute solution of water glass, which effects a surface silicification. In one example, solutions of potassium tungstate, sodium vanadate, and potassium molybdate are mixed and poured into a suspension of asbestos in a solution containing potassium silicate and phosphate, whereafter there is added a solution of sodium vanadite. The mixture is treated gradually with sulphuric acid until a, gel is formed and the mass is then washed, treated with hydrochloric, sulphuric, or phosphoric acid, dried, and calcined in air. The product is useful as a catalyst in the production of benzaldehyde and benzoic acid from a mixture of toluene and an oxygen-containing gas, such as a mixture of carbon dioxide and oxygen; the process may be effected in a circulatory system. In another example, a suspension of cobalt-impregnated pumice or asbestos in sodium silicate solution is mixed with the suspension of iron vanadate and iron oxide obtained by adding ferrous sulphate to an alkaline solution of sodium vanadate, and to the mixed suspensions there is added a solution of sodium vanadite. The product, after treatment as described in the previous example, may be used as a catalyst in the production of anthraquinone from a mixture of anthracene, vapour and air; acenaphthene and its halogen derivatives may be oxidized similarly to naphthalic anhydride and corresponding derivatives. In another example, lead is introduced by base-exchange into an ordinary artificial or natural zeolite, and the product is treated with potassium vanadate. The resulting salt-like body, after drying and calcining, may be used as a catalyst in the production of acenaphthylene from a mixture of acenaphthene vapour and air. Instead of lead there may be introduced into the zeolite copper, nickel, cobalt, silver, manganese, chromium, or aluminium, and instead of potassium vanadate, an acid derived from another metal of the fifth or sixth periodic group may be used. The products are then useful as catalysts in the vapour-phase production of maleic and fumaric acids from mixtures of air with benzene, toluene, phenol or tar acids, and also in the oxidation of o- and p-chlor- and brom-toluenes, dichlortoluenes, chlorbromtoluenes, nitrotoluenes, and chlor-and brom-nitrotoluenes to the correspondaldehvdes and acids. In the oxidation of nitrotoluenes, inert gases should be present, and the contact mass should be cooled. In a further example, a suspension of celite in sodium silicate solution is mixed with solutions of potassium vanadate and aluminate. The product, after treatment, as described in the first example above, may be used as a catalyst in the production of phthalic anhydride from a mixture of naphthalene vapour and air. In another example, a solution of potassium vanadate and/or vanadite is added to an aqueous suspension of celite, with or without broken quartz, pumice, glass, neutral silicates, or asbestos, and vanadium pentoxide and/or tetroxide is precipitated on the suspended material by addition of sulphuric acid. The product, after separation and drying, is kneaded in potassium silicate solution, and may then be prepared for use as a catalyst in the vapour-phase oxidation of anthracene to anthraquinone, or of toluene and its homologues, such as xylene, mesitylene, pseudocumene, and cymene to the corresponding aldehydes. For the oxidation of anthracene, the catalyst may be digested in a ferric sulphate or chloride solution in order to introduce iron by base-exchange. Alternatively, the catalyst may be sprayed with a solution of vanadyl sulphate and then calcined in air, when it becomes suitable for use in the vapour-phase oxidation of naphthalene to phthalic anhydride. In another example, a suspension of pumice, quartz, or natural zeolites in potassium vanadate solution is treated with silver nitrate and neutralized, whereby silver vanadate is precipitated on the suspended substances. Solutions of potassium silicate and vanadyl sulphate are then added in turn, and the product, which comprises metallic silver, is separated and broken up. It may be used as a catalyst in the production of formaldehyde from methyl alcohol or methane, or acetic acid from ethyl alcohol, of chloracetic acid from ethylenechlorhydrin, and of maleic and fumaric acids from tar acids. In a further example, a potassium silicate solution is added to a suspension of the precipitated oxide of tantalum, tungsten, and uranium, the mass setting to a gel which is separated and broken up. The product may be used in the catalytic oxidation of toluene and its derivatives to the corresponding aldehydes. In another example, molybdic oxide is precipitated on kieselguhr. and the product is treated with potassium silicate solution and ammonium sulphate. The gel formed is separated, rendered acid with sulphuric or phosphoric acid, and calcined: it may be used to promote the vapour-phase oxidation of naphthalene to phthalic anhydride. In another example, a suspension of copper carbonate in silver nitrate solution is treated with ammonia, until a solution is obtained, whereafter there are added an ammoniacal solution of sodium silicate and then nitric acid until the mass sets to a gel. The dried product is treated with silver nitrate. in order to introduce silver by baseexchange, and finally is sprayed with ammonium vanadate solution and calcined. It may be used as a catalyst in the production of formaldehyde from methyl alcohol. In a further example, the sodium of an ordinary artificial or natural zeolite is exchanged for lithium, potassium, rubidium. and/or caesium, whereafter the zeolite is first sprayed with ammonium vanadate and/or molybdate solution and then treated with a solution containing ferrous chloride and sulphate. Finally the product is calcined at 400-450‹ C., first in air, then in a stream of air containing sulphur dioxide until sulphur trioxide begins to be formed, and then again in air. The product promotes the production of anthraquinone from anthracene, and of naphthalic anhydride and hemimellitic acid from acenaphthene. The ferrous chloride and sulphate used in this example may be replaced by solutions of silver or copper salts, in which event the products are of use in the oxidation of benzene to maleic acid and of methyl alcohol to formald