Development of Pt/ASDBC Catalyst Applicable for Hydrogen Oxidation in the Presence of Saturated Water Vapor at Room Temperature

Combined catalytic recombiner and water absorber system has been applied in a tritium handling facility to remove tritium as well as other tritiated components in the atmosphere of a containment. It has been known that the hydrogen oxidation performance of the catalyst packed in the catalytic recombiner considerably decreased at room temperature in the case where the concentration of water vapor is very large. We have developed some hydrophobic Pt catalysts applicable for hydrogen oxidation even in the presence of saturated water vapor at room temperature. A new type of hydrophobic catalyst, Pt/ASDBC, has been prepared by depositing platinum on alkyl-styrene diviyl-benzene copolymer (ASDBC). Pt/ASDBC is more hydrophobic than Pt/SDBC that is the standard catalyst for a water detritiation system. Oxidation tests of the catalysts using 10000 ppm of hydrogen were performed in the presence of saturated water vapor at room temperature. Hydrogen oxidation more than 99% was achieved using Pt/ASDBC catalyst in the range of space velocity from 320 to 3300 h. Moreover, radiation technology was applied to extend the pore size of catalyst. Hydrogen oxidation performance has been much improved with Pt/ASDBC catalyst irradiated with electron beams.