| 摘要 |
A composite metallic member comprises a metallic base coated with a double skeleton catalyst layer consisting of 99 to 5% of a porous electronically conducting supporting catalyst and 1-95% of a Raney metal, the coating being bonded to the base by sintering and then etched by an alkaline or acid solution so that Raney metal particles remain embedded in the supporting skeleton. The metal base which may be solid or porous and the supporting skeleton consist of one or more metals from Groups I to VIII of the Periodic Table and/or an alloy of one or more of these metals and the Raney metal is a metal of one of these groups with optionally up to 50% by weight of an activating agent such as Cu, Pd, Pt, Al2O3, ZnO or LiO for Raney Ni, Cr, Mn, V, Nb, Pt, OS or MnO2 for Raney Ag, Ni or NiO for Raney Cu, and Cu, Ni, W or WC for Raney Mo. The powdered coating materials are applied to the roughened metal base by cold pressing or rolling and sintering above 400 DEG C., preferably at 600 DEG -1100 DEG C. in a hydrogen atmosphere, or by hot pressing or rolling at 400 DEG -600 DEG C. A volatile material such as citric acid, oxalic acid or ammonium carbonate may be added as a pore former and the supporting skeleton material may be applied to the base and sintered separately prior to applying the Raney alloy, or the powdered mixture of the skeleton and the Raney alloy may be applied together. The skeleton material particle size should be between 1 to 200 micron and the Raney alloy particles size should be less than half the pore diameter of the supporting skeleton. Alternatively the porous supporting skeleton may be formed by either of the following methods: (a) etching the base with acid or alkali; (b) oxidizing and then reducing the surface of the metal base; (c) galvanic erosion of the metal base; (d) treating the metal surface with carbon monoxide; (e) by electrolytic deposition. In the examples the soluble component of the Raney alloy is Al and the alloy compositions are Ni/Al 50 : 50 and Ag/Al 65 : 35, although zinc and magnesium may also form the soluble constituent of the Raney alloy. Specifications 907,907 and 908,436 are referred to. |
