EN
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.