Patent ID: 6034030
Filing Date: 2000-03-07
Classification: B01J,C07C

Abstract:
In a method of preparing a catalyst composed of a porous support containing thereon palladium and gold metals comprising; impregnating said support with water soluble compounds of such precious metals, converting said absorbed water soluble precious metal compounds to water insoluble precious metal compounds by contacting the impregnated support in a fixing step with a solution containing a compound reactive with said water soluble precious metal compounds to precipitate on said support water insoluble precious metal compounds and reducing said water insoluble precious metal compounds with a reducing gas to form free precious metals on said support, the improvement which consists in ( 1) contacting said supports with one of said water soluble compounds of said precious metal to impregnate the water soluble compound on the support (2) converting said water soluble precious metal compound to water insoluble precious metal compound by contacting said impregnated support in a first fixing step with a solution containing a compound reactive with said water soluble compound to precipitate on said support said water insoluble precious metal compound (3) contacting said first impregnated and fixed support with the second of said water soluble compounds of said precious metal to impregnate the water soluble compound on the support (4) converting said second water soluble compounds of said precious metals to water insoluble precious metal compound by contacting said impregnated support in a second fixing step with a second solution containing a compound reactive with said second water soluble compound to precipitate on said support said second water insoluble precious metal compound, and thereafter reducing said water insoluble precious metal compounds to form free precious metals on said support.