Characteristics of honeycomb catalysts for oxidation of tritiated hydrogen and methane gases

For large volume air cleanup in a nuclear fusion facility, honeycomb catalysts offer a useful advantage in terms of their low-pressure drop. In the present study, characteristics of honeycomb catalysts for oxidation of hydrogen and methane gases were examined. The catalysts used were cordierite or Al–Cr–Fe metal alloy honeycombs on whose surface the precious metals Pt or Pd were deposited. Experimental parameters were the weight ratio of precious metal, mesh density, and water vapor content of the processed gas. It was found that Pt was suitable for hydrogen oxidation and Pd for methane oxidation. The oxidation reaction rate depended mainly on the precious metal weight ratio but not significantly on mesh density, and increasing the moisture content decreased the oxidizing activity. These honeycomb catalysts could be used as a high-performance alternative to a conventional packed bed type of catalyst in air cleanup systems.