Patent GB-1289354-A (GB)
IPC: C01F7/00
Filed: 1969-09-12
Abstract: 1289354 Preparation of catalysts CHIYODA KAKO KENSETSU KK 12 Sept 1969 [14 Sept 1968] 45219/69 Heading B1E [Also in Divisions C1 and C5] A catalyst consisting of alumina having dispersed therein at least one metal or oxide thereof, the or each metal having a higher standard reduction single electrode potential than that of aluminium, is prepared from at least one complex having the empirical formula Al n M' n (OH) m X 3n+p-m , wherein M represents at least one metal having a higher standard reduction single electrode potential than that of aluminium, X represents at least one monovalent anion, n, n' and m are integers, p is the product of n' and the valency of the metals M, the ratio of n to n' is greater than or equal to unity and 3n+p-m is positive, by drying and calcining either an aqueous solution of the complex(es) or a gel obtained by contacting an aqueous solution of the complex(es) with a weak base preferably having a dissociation constant lower than 10<SP>-4</SP>, for example ammonia, ammonium bicarbonate, ammonium carbonate, urea, ethylenediamine, hexamethylenetetramine, diethanolamine or triethanolamine, or or precipitate obtained by contacting an aqueous solution of the complex(es) with a weak base preferably having a alkali metal hydroxide, an alkali metal carbonate or a carbonate which is strongly alkaline in aqueous solution, or a mixture of at least two such gels or precipitates. The aqueous solution may contain two or more complexes which contain either the same metal(s) or different metal M. The or each complex may be prepared either from (a) an aqueous solution containing a salt of the metal M and, optionally, an aluminium salt and (b) elemental aluminium or aluminium hydroxide or from (a) an aqueous solution containing a salt of the metal M and (b) an aluminium complex having the empirical formula Alq (OH) r X 3q -  r , wherein X represents at least one monovalent anion, q and r are integers, q is greater than 1 but not greater than 6 and 3q-r is positive. Drying may be effected at a temperature of from 60 to 120‹C; calcining may be effected at a temperature of from 120 to 1400‹C. A catalyst containing the metal(s) M in oxide form is prepared by calcining in an oxidising atmosphere; a catalyst containing the metal(s) M in elemental form is prepared either by calcining in a reducing atmosphere or by treating a catalyst containing the metal(s) M in oxide form in a reducing atmosphere. Metals M exemplified are titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, arsenic, zirconium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, indium, tin, antimony, tungsten, osmium, iridium, platinum, gold, mercury, thallium, lead, bismuth, metals of the lanthanide. series and metals of the actinide series including thorium and uranium; anions X exemplified are chloride, bromide, iodide, nitrate, nitrite, perchlorate and carboxylate RCOO- wherein R is a hydrogen atom or a methyl, ethyl or propyl group. Examples relate to the preparation of alumina having dispersed therein either chromium oxide (Examples 1, 2 and 3) or nickel oxide or elemental nickel (Examples 4, 5 and 6) or oxides of cobalt and molybdenum in combination (Examples 7, 8, 9, 10 and 19) or platinum (Examples 11, 12 and 13) or iron oxide (Examples 14 and 21) or manganese oxide (Example 15) or zirconium oxide (Example 16) or tin oxide (Example 17, or thorium oxide (Example 18) or oxides of nickel and molybdenum in combination (Example 20). The catalyst may be used in the dehydrogenation of propane to propylene, in the hydrogenation of benzene and in the hydrodesulphurization of petroleum fractions.