The thermal effects and activity of SiO2 and MoO3 supported bimetallic Pd-Pt catalysts (Pd:Pt = 1) in the exothermic H2 and O2 recombination reaction have been investigated in view of their potential use in the passive autocatalytic recombiners (PAR), which are applied at an industrial stage of development in the nuclear plant to lower the explosion risk associated with hydrogen release. The catalysts have been prepared using the colloid-based reverse “water-in-oil” microemulsion method and characterized by BET, XRD, SEM, EDS techniques. The recombination reaction of hydrogen and oxygen has been monitored using Microscal gasflow through microcalorimeter. This technique was also applied to follow hydrogen sorption by the Pd-Pt/ MoO3 catalyst resulting in the formation of molybdenum bronzes (HXMoO3). The pattern of changes in both the heat evolution and the conversion of hydrogen clearly show much better performance of Pd-Pt/SiO2 catalyst. On Pd-Pt/ MoO3 catalyst the conversion of H2 was lower whereas the amount of evolved heat was higher because of exothermic reaction of bronzes formation. In contrast to Pd-Pt/SiO2 catalyst offering stable activity, the activity of Pd-Pt/MoO3 decreased during the catalytic test.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.