Synthesis, Characterization and Application of Thermostable Hydrophobic Pt Catalysts for Oxidation of H2

Abstract

The studies were aimed at the development of thermostable hydrophobic Pt catalyst for hydrogen oxidation in the close-to-stoichiometric mixture with oxygen to provide the high gas conversion at the temperature not higher than 353 K in the direct contact with water. The catalyst is to be used for utilization of radiolytic gases (hydrogen and oxygen) at atomic power stations. The studies were focused on the Pt/Al₂O₃ type catalyst with a modified surface. Modified γ-Al₂O₃ was used for preparation of catalysts containing 0.5 wt% of platinum. The catalyst hydrophobicity, thermal stability, texture, surface composition, catalytic performance for hydrogen oxidation, and operational stability were studied during 50-hour testing. The established properties of the catalyst were thermal stability up to 773 K, superhydrophobic surface, reaction rate constants no less than 4±1 s^–1 (at 333 K). The oxidation efficiency was no less than 99.999 % at the hydrogen flow rate of 50 L/h. The results obtained demonstrate potentialities of the prepared hydrophobic catalyst and of the technology for hydrogen oxidation over this catalyst.