Patent GB-937748-A (GB)
Title: Metal loading of molecular sieves
IPC: B01J20/18
Filed: 1959-09-23
Abstract: A zeolitic molecular sieve is loaded with adsorbed metal by contacting the zeolite with an aqueous solution of a metal amine the cations of which are taken up by the sieve by ion exchange, and thereafter removing adsorbed water in an inert atmosphere and reducing the complex cations in the dehydrated sieve to elemental metal either by thermal reduction or chemical reduction with for example hydrogen or sodium.  Metals specified are Cu, Ag, Au, Cr, Zn, Cd, Sn, Pb, Fe, Co, Ni, Ru, Rh, Pa, Os, Ir and Pt; the sieves so loaded may be treated with oxygen to convert the metal content of the sieve to oxide.  Suitable zeolitic sieves are the natural zeolites faujasite and erionite and synthetic zeolites X, Y, L and T described in Specifications 777,233, 909,266, 909,264 and 912,936 respectively. According to Examples (1) hydrated zeolite X powder was added to an aqueous solution of tetramine platinous chloride hydrate and after contact for an hour was filtered and washed successively with water, alcohol and ether and then air dried.  The complex was thereafter heated at 375 DEG C. in hydrogen to evolve ammonia and reduce platinium to the metallic state. Hydrogen cations had replaced the complex cations that had been taken up and then decomposed by the heat treatment (2) Tris (ethylenediamine) chromium (III) sulfate was added to hydrated solium zeolite X and after filtering as in (1) above the ion exchanged product was heated to 350 DEG C. to decompose the complex ion and remove the amine after which the temperature was reduced to 170 DEG C. and molten metallic sodium added in an argon atmosphere. Chromium metal was deposited in the structure of the sieve and the chromium cation was replaced by sodium cations.  On contact with air the contained chromium oxidized.  (III) Zeolite T was contacted with a solution of tetramine platinous chloride hydrate and the ion exchanged product was dried at 100 DEG C. and thereafter heated at 350 DEG C. in hydrogen.  The final zeolite containing 0,8% by weight of platinum was added to a mixture of pentene-1 and cyclohexane and the mixture was contacted with hydrogen at 47 psig. Hydrogenation of the pentene was effected.  (V) Zeolite X was contacted with an aqueous solution of bis(ethylenediamine) auric chloride and after washing the loaded zeolite was heated to 375 DEG C. to obtain a zeolite containing 15% of metallic gold.  (VI) A palladium amine chloride complex was prepared by distilling palladium chloride in concentrated ammonia and the solution was heated to remove excess ammonia and contacted with zeolite X, after which the loaded zeolite was heated to 375 DEG C. in air to yield a molecular sieve loaded with 5,7% of palladium metal. (VII) A ruthenium amine complex was prepared by adding aqueous ammonia to an aqueous solution of ruthenium chloride and boiling; a solution of zeolite X was added and the product after filtering was dried at 100 DEG C.  Further heating resulted in a ruthenium metal-loaded zeolite containing 7% by weight of ruthenium.  (VIII) Zeolite Y was contacted with tetramine platinous chloride hydrate and the product after washing was dried at 110 DEG C. and the amine complex cation decomposed by heating at 400 DEG C.  The metal loaded sieves are suitable as catalysts and as selective getters; they may also be employed as a means for the controlled addition of metals to reaction systems.  Specifications 937,749 and 937,750 also are referred to.