Variation in noble metal morphology and its impact on functioning of hydrogen mitigation catalyst

A large amount of hydrogen is generated in nuclear reactor during loss of coolant accident (LOCA) conditions. This can be a threat to containment integrity if flammable limit (4% in air) is crossed. Passive autocatalytic recombiner is one of the most feasible remedies for this. Here we report a new class of mixed noble metal catalysts prepared by modified methods, viz Pt, Pt + Pd or Pt followed Pd on stainless steel wire gauze. These catalysts were characterised for noble metal loading, phase purity by XRD, morphology of surface by Scanning Electron Microscopy (SEM). They were then evaluated for their catalytic activity for H2–O2 recombination reaction under static air condition and in presence of various poisons like carbon dioxide, methane, carbon monoxide and water.

► Mixed Pt–Pd catalysts prepared from a single electroless deposition bath. ► Catalysts found to active for H2–O2 recombination reaction. ► Catalytic activity is not affected by various poisons CO and moisture. ► The surface morphology of deposition consists of rough and round agglomerates.