Ali Khodayari - Department of Chemistry, University of Mohaghegh Ardabili, Ardabil, Iran
Ebrahim Alizadeh-Gheshlaghi - Department of Inorganic Chemistry, Faculty of Chemistry, Tabriz University, Tabriz, Iran

Metal oxide nanoparticles exhibiting interesting optical and electrical properties that can be grown efficiently as powder nanostructures are used extensively for variety of applications in catalysis, sensors, and environmental remediation and optoelectronic devices [1]. Nano-sized Co3O4 has a wide range of applications in various fields of industry including anode materials for rechargeable Li-ion batteries [2], gas sensors, solid state sensors, ceramic pigments, heterogeneous catalysts, rotatable magnets, electrochromic devices, magnetic materials and in energy storage [3]. Ammonium perchlorate (AP) is the most common oxidizer agent in composite solid propellants. The thermal decomposition characteristics influence the combustion behaviour of the propellant. The activation energy, reaction rate, high‐temperature decomposition (HTD) and pyrolysis temperature of the thermal decomposition of AP are related to the properties of solid propellants, especially the heat absorption and combustion rate[1]. Among various catalysts, Co3O4 nanostructures have attracted a great deal of attention in both fundamental researches and technical applications because of their outstanding catalytic, electrical conductivity, chemical stability, low cost, and other properties. In this study, semi-spherical Co3O4 nanostructures were successfully synthesized using a facile sol-gel synthetic route at 100 °C under refluxing conditions and characterized by XRD, FTIR, SEM and TEM. The results showed that the Co3O4 nanoparticles were in pure face centered cubic (FCC) crystal phase and composed of many semi-spheres of diameter about 20 nm which are assembled and they formed micro-sphere morphology. Thermocatalytic properties of Co3O4 nanostructures investigated on thermal decomposition of AP using DSC curves. The results reveal that adding 1% of Co3O4 nanostructures to AP, decreases the temperature of HTD amount 92 °C (425 °C to 331 °C) and increases the heat absorption amount 889 J g−1 (redox decomposition of AP). Two major mechanisms have been proposed for the thermal decomposition of AP in the presence of Co3O4 nanostructures, first: electron transfer from perchlorate ion to ammonium ion, Second: proton transfer from ammonium ion to perchlorate ion.