Patent ID: 7595087

Claim:
A process of forming a platinum coating catalyst layer in a moisture-generating reactor, comprising the steps of: (a) providing a reactor body part made of an alloy containing aluminum; (b) forming a principally aluminum oxide (Al 2 O 3 )-composed barrier film on an inner wall surface of the reactor body part by applying an aluminum selective oxidation treatment; and (c) applying a platinum layer to the barrier film to form the platinum coating catalyst layer, wherein a stainless steel alloy containing aluminum is employed for the alloy containing aluminum and wherein the aluminum selective oxidation treatment of the alloy containing aluminum is effected by a heating treatment comprising the steps of i. heating for a prescribed time, and ii. providing a treatment atmosphere comprising a ratio of hydrogen-to-moisture (H 2 /H 2 O) of 10 4 :1 to 10 9 :1 and a heating temperature of 300° C. to 1500° C., wherein the barrier film which forms part of the platinum coating catalyst layer comprises an almost 100% aluminum oxide (Al 2 O 3 ) layer on the alloy containing aluminum forming the inner wall surface of the reactor body part and a principally aluminum oxide (Al 2 O 3 )-composed layer on at least some of the alloy containing aluminum forming an outer surface of the reactor body part.