Thermochimica Acta, Vol.275, No.1, 83-91, 1996
The Role of Copper Cobaltite Spinel, Cuxco3-xO4 During the Thermal-Decomposition of Ammonium-Perchlorate
The catalytic effect of copper cobaltite, CuxCo3-xO4 spinel in the range (0 less than or equal to x less than or equal to 3) on the thermal decomposition of ammonium perchlorate (AP) has been studied using thermogravimetry (TG) and differential thermal analysis (DTA). The results revealed that the addition of CuO (x = 0.1 or 0.3) led to an observable increase in the catalytic activity of Co3O4 towards the decomposition of AP, while the activity of CuO decreases at x = 2.9 and 2.7. The creation of more holes within the p-type semiconducting catalyst is responsible for enhancing the decomposition of AP. In contrast, the catalysts containing copper cobaltite spinels are less active than the doped catalysts. The active redox sites established in these spinels, Co3+/Co2+, Cu2+/Cu+ and Co3+/Cu+, are not as efficient as holes in promoting electron exchange with the perchlorate ions.