Catalytic oxidation and adsorption is conventional and reliable method for the detritiation of air in the working area of fusion power plants. Most commercial catalysts widely used for oxidation are fabricated using alumina substrates. However, in terms of the adsorption for tritiated water vapors, zeolites could have better performance. Thus, the authors conducted test fabrication of noble metal catalysts of which substrates are A-type zeolites and examined their catalytic performance for the oxidation of hydrogen and methane. The results indicate that these newly developed catalysts have excellent catalytic activity for the oxidation of hydrogen and their performance exceeds or is comparable to that of commercial Pd/alumina catalysts. Furthermore, it was also found that these catalysts have lower catalytic activity for the oxidation of methane compared with the commercial Pd/alumina catalysts. This result reveals a possibility that these catalysts can be utilized for the selective oxidation of molecular tritium and tritiated methane, which could be useful for monitoring of environmental tritium.