Effect of manganese dioxide on the thermal decomposition of ammonium perchlorate

Thermal decomposition of powdered ammonium perchlorate, catalysed by manganese dioxide (MnO₂), has been studied in the low concentration ranges of the catalyst. MnO₂ sensitises the thermal decomposition of ammonium perchlorate. The activation energy estimations of catalysed ammonium perchlorate show that the value is about 30 kcal/mol throughout the low and the high temperature regions whereas uncatalysed ammonium perchlorate gives two activation energies, 20 kcal/mol in the low temperature region (280–320°C) and 60 kcal/mol in the higher temperature region (350–390°C). This behaviour has been explained on the basis of an electron transfer process. The effectiveness of MnO₂ in the thermal decomposition further increases on pre-heating the sample at 50°C for two weeks; manganese ions enter the ammonium perchlorate lattice during the process of pre-heating.