PREPARATION OF PLATINUMMSUPPORTED METAL CATALYST FOR OXIDATION

摘要

PURPOSE:To prevent dissolution of iron in a soln. of chloroplatinic acid for dipping by adjusting the soln. to a specific pH value with NaOH before dipping a catalyst substrate in the soln. CONSTITUTION:A metallic material of a predetermined shape such as ring or honeycomb shape is plated with Al, heat treated at a temp. above the m.p. of Al for several min-several hr to diffuse the Al in the outer layer of the material, dipped in an Al dissolvable soln. to elute the Al, and oxidized at room temp. -400 deg.C in an atmosphere contg. 0.1-20.8vol% oxygen for 0.1-2.0hr. The resulting catalyst substrate is then dipped in an aq. soln. of chloroplatinic acid contg. 0.01-1.0wt% platinum adjusted to pH about 9-10 with NaOH, introducing the platinum into the substrate. The platinum contg. catalyst substrate is dried at a temp. above 100 deg.C to obtain platinum-supported oxidation catalyst.