Catalytic Effect of Potassium Hydroxide and Its Adduct with Superoxide on the Thermal Decomposition of Potassium Perchlorate and Chlorate

The decomposition of KClO(4) and KClO(3) in the presence of KOH and KOH center dot KO(2) is studied. KOH is found to accelerate thermal decomposition of potassium perchlorate and chlorate by 6 and 1.5 orders of magnitude, respectively. At the ratio KClO(n) : KOH = 1 : 2, the chlorate decomposes in one step to KCI and O(2), whereas perchlorate decomposition consists of two successive reactions KClO(4) -> KClO(3) -> KCl. Both processes obey the first-order rate equations. The Arrhenius parameters for the decomposition reaction of KClO(4) in the presence of KOH are E(a) = 47.2 +/- 1.3 kcal/mol, logA = 14.63 +/- 0.48 min(-1), and E(a) = 48.9 +/- 0.8 kcal/mol, logA = 13.67 +/- 0.27 min(-1) for KClO(3). In the presence of KOH, the decomposition of KClO(4) proceeds 25 to 30 times faster than that of KClO(3). Without catalysts, the chlorate decomposes faster by approximately two orders of magnitude. The effect of the mixed catalyst KOH + KO(2) in the studied temperature range 310-380 degrees C is close to the efficiency of KO(2) alone, although the activation energy is more close to that for the processes with KOH. Unlike lithium and sodium hydroxides, potassium hydroxide does not form adducts with potassium perchlorate, chlorate, or chloride.