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Chemical compositions for emergency oxygen generators typically include sodium chlorate (NaClO 3 ) as the oxygen source, transition metal oxide as catalyst for NaClO 3 decomposition, and metal fuel to provide energy for self-sustained combustion. To clarify the role of metal fuel in the combustion mechanism, potential catalytic effects of metals on NaClO 3 decomposition are investigated. Thermal analysis was conducted in argon flow for binary NaClO 3 /Me mixtures, where Me ) Al, Fe, Co, Ni, and Sn, as well as in oxygen flow for metal powders alone and mixtures of NaClO 3 with Sn and Co. The experiments show that catalytic effects of metals on NaClO 3 decomposition range from negligible for Al and Sn, to significant for Co and Ni, while Fe exhibits moderate catalytic activity. Thermodynamic calculations indicate that replacement of Sn with Co or Ni does not significantly alter combustion characteristics, which determine product oxygen flow rate. Replacing Sn with Co or Ni may decrease the number of ingredients in oxygen generators, since these metals both catalyze and fuel the process.

Decomposition of sodium chlorate catalyzed by iron oxide in the presence of barium peroxide and hydroxide is studied by thermogravimetric analysis. Barium peroxide and hydroxide are moderately active catalysts by themselves but are inhibitors when used together with iron oxide. A loading of 1% barium peroxide or hydroxide can significantly reduce the activity of the iron oxide and raise the decomposition temperature of sodium chlorate. The inhibiting effect decreases with increased loading of the barium compounds due to the formation of barium ferrate. The catalytic activity change of the iron oxide in the presence of barium peroxide and hydroxide is discussed based on the electron configuration change of the iron ions.

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