UN METODO DE PREPARACION DE UN COMPUESTO CATALITICO.

摘要

1305134 Supported catalysts comprising germanium UNIVERSAL OIL PRODUCTS CO 19 May 1970 [28 May 1969] 24135/70 Heading B1E A hydrocarbon conversion catalyst is prepared by a process which comprises the sequential steps of (a) contacting germanium dioxide with hydrogen at a temperature of from 500 to 850‹C to provide a grey reduction product, (b) dissolving the reduction product in an aqueous solution of chlorine to provide a germanium-containing solution, (c) impregnating porous carrier material with the solution, for example at a temperature of from 10 to 38‹C, (d) drying the impregnated carrier material, for example at a temperature of from 93 to 316‹C, and (e) calcining the -dried impregnated carrier material, for example in air at a temperature of from 371 to 593‹C, at least a portion of the calcining preferably being effected in an atmosphere containing halogen or a halogen-containing compound, for example hydrogen chloride, and optionally water vapour. Prior to impregnating the carrier material therewith, it is preferred to adjust the pH of the solution to a value of from 1 to 7 by adding thereto an acid, for example hydrochloric acid or nitric acid, and to dilute the solution to a volume which is greater than the volume of carrier material to be impregnated. Group VIII noble metal selected from rhodium, ruthenium, palladium, osmium, iridium and platinum may be incorporated in the catalyst by adding a soluble decomposable compound of a Group VIII noble metal to the solution before impregnating the carrier material therewith; alternatively, the carrier material may be impregnated with a solution containing such a Group VIII noble metal compound and thereafter dried and calcined either before step (c) or after step (d) or after step (e). Calcined material containing germanium and Group VIII noble metal may be subjected to reduction at a temperature of from 427 to 538‹C with substantially water-free hydrogen to reduce the Group VIII noble metal component to the metallic state while maintaining the germanium component in a oxidized state; the reduced material may be treated at a temperature of from 10 to 538‹C with a gas mixture containing hydrogen and a sulphurcontaining compound, for example hydrogen sulphide, an organic sulphide or a mercaptan, to incorporate from 0.05 to 0.50 weight per cent of sulphur in the material. The catalyst may contain from 0.01 to 5.0 weight per cent of germanium, from 0.01 to 2.0 weight per cent of Group VIII noble metal and from 0.5 to 4 weight per cent of halogen, for example chlorine. Exemplified carrier materials are activated carbon, coke and charcoal; natural and synthetic, optionally acid-treated, clays and silicates, for example attapulgus clay, china clay, kaolin, fuller's earth, diatomaceous earth, keiselguhr and pumice; ceramics, porcelain and crushed firebrick; bauxite; magnesia, zinc oxide, boria, gamma-, eta- and theta-aluminas (including alumina containing minor proportions of refractory material selected from magnesia, silica and zirconia), silica, for example silica gel, titania, zirconia, thoria, chromium oxide, alumina-boria, aluminachromium oxide, silica-magnesia, silica-alumina and silica-zirconia; natural and synthetic mordenite and faujasite, optionally in the hydrogen or multivalent cation-exchanged form; and combinations of such materials. The carrier material may have a surface area of from 25 to 500 m2/g; a preferred carrier material is gamma-alumina having a surface area of from 100 to 500 m2/g, an apparent bulk density of from 0.30 to 0.70 g/cm3, an average pore diameter of from 20 to 300 Angstroms and a pore volume of from 0.10 to 1.0 cm3/g. According to the single example, catalyst containing 0.25 weight per cent of germanium, 0.375 weight per cent of platinum and 0.85 weight per cent of chlorine supported on gamma-alumina is prepared by contacting germanium dioxide powder with hydrogen at 650‹C, dissolving the resulting grey solid in an aqueous solution saturated with chlorine, adding chloroplatinic acid and hydrogen chloride to the solution, impregnating 1.6 mm spheres of gamma-alumina (prepared from basic aluminium chloride by a conventional oil drop procedure) with the solution at 21‹C, the volume of the solution being twice the volume of the spheres, and subjecting the impregnated spheres successively to drying at 149‹C, calcining at 524‹C initially in air and thereafter in an air stream containing water and hydrogen chloride in a mole ratio of 40 to 1, and reducing at 538‹C in a hydrogen stream containing less than 20 volume parts per million of water. Reference is made to Specification 1305133 which discloses, inter alia, details relating to the use of such catalysts in hydrocarbon conversion reactions.