Manufacture of hydrogenation catalyst composition

PURPOSE: To produce a catalyst for selectively hydrogenating acetylene to ethylene by bringing a catalyst composition comprising palladium, silver and a supporting material into contact with a liquid composition comprising a reducing agent at a comparatively low temperature. CONSTITUTION: A solid composition comprising palladium, silver and an inorganic supporting material such as alumina or the like is used. A liquid reduction composition prepared by dispersing a reducing agent containing hydrazine, an alkali metal boron hydride, an aldehyde containing 1-6C per molecule and the like in a non-reducing liquid such as water, alcohol or the like is brought into contact with the slid composition at about 60 deg.C for at least about 1 second so as to obtain a wet-reduced solid composition. Then, the solid composition is separated and dried. If the reducing agent is an aldehyde, a ketone or the like, an alkali metal compound such as an alkali metal hydroxide or the like is added, and if the reducing agent is a sugar, heating at about 300-700 deg.C for at least about 10 minutes is performed in an oxidizing atmosphere.