Patent GB-1345611-A (GB)
Title: Preparation of a catalytic composite containing germanium and  platinum group metal and use thereof for the conversion of  hydrocarbons
IPC: B01J23/62
Filed: 1971-04-27
Abstract: 1345611 Hydrocarbon conversion catalysts UNIVERSAL OIL PRODUCTS CO 27 April 1971 11564/71 Heading B1E [Also in Division C5] A hydrocarbon conversion catalyst comprising a germanium component and a Group VIII noble metal component uniformly dispersed throughout porous carrier material is prepared by a method which comprises the sequential steps of (a) mixing germanium tetrachloride with a substantially anhydrous alcohol, for example an aliphatic monohydric alcohol containing from 1 to 10 carbon atoms, (b) establishing in the resulting solution an equilibrium condition such as by ageing at ambient or elevated temperature, for example for 1 to 4 days at ambient temperature or for 1 to 5 hours at 70‹C, (c) mixing the resulting equilibrated solution with an aqueous solution of a decomposable water-soluble compound of a Group VIII noble metal selected from ruthenium, rhodium, palladium, osmium, iridium and platinum, (d) impregnating porous carrier material with the resulting precipitate-free solution, (e) drying the impregnated carrier material, for example at a temperature of from 93 to 316‹C, and (f) 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 precipitate-free solution to a value of from 1 to 7 by adding thereto a mineral acid or organic acid, for example hydrofluoric acid, hydrochloric acid, hydrobromic acid and nitric acid. The calcined material may be contacted with substantially water-free hydrogen at a temperature of from 427 to 593‹C thereby to reduce the Group VIII noble metal component to the metallic state while maintaining the germanium component in a positive oxidation state; the reduced material may be treated at a temperature of from 10 to 538‹C with a gas mixture containing hydrogen and a sulphur-containing compound, for example hydrogen sulphide, an organic sulphide or a mercaptan, to incorporate from 0.05 to 0.5 weight per cent of sulphur in the material. The catalyst may contain, expressed on an elemental basis, from 0.01 to 5 weight per cent of germanium, from 0.01 to 2 weight per cent of Group VIII noble metal and from 0.5 to 4 weight per cent of halogen selected from fluorine, chlorine, bromine and iodine. Exemplified and preferred carrier materials are those carrier materials disclosed in Specification 1,332,734. As exemplified, catalyst containing 0.25 (or 0.5) 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 dissolving germanium tetrachloride in ethanol containing less than 0.5 volume per cent water (or in isopropanol containing less than 0.1 weight per cent water), ageing the resulting solution for 4 days at ambient temperature, mixing the aged solution with aqueous chloroplatinic acid solution and hydrogen chloride, impregnating 1.6mm. spheres of gamma-alumina (prepared from basic aluminium chloride by a conventional oil drop procedure) with the resulting 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 initially at 425‹C in air and thereafter at 524‹C 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 also to Specification 1,345,612.