Enhanced Catalytic Behavior of La2o2co3/Co3o4 Composite for Ammonium Perchlorate's Thermal Decomposition

Abstract

In this work, La2O2CO3, Co3O4 and their La2O2CO3/Co3O4 composites were prepared by one-step solution combustion with citric acid as oxidant and lanthanum nitrate and cobalt nitrate as reductants. Many pores of different sizes were found on the surface of the composite by morphology analysis. The catalytic performance of the La2O2CO3/Co3O4 composite was found to be the best. The high decomposition temperature (HDT) of AP decreased by 187.7 ℃, and the activation energy decreased from 371.6 to 140.6 KJ·mol-1. The combustion process of AP/HTPB solid propellant containing La2O2CO3/Co3O4 was more intense, the ignition delay time was shortened from 30 ms to 25 ms, and the time to reach the maximum combustion effect was advanced from 370 ms to 190 ms. Through mechanism analysis, we believe that La2O2CO3 accelerates the decomposition of AP at low temperature by promoting the cleavage of N-H bond in NH3. Co3O4 has unfilled 3d orbitals, which could accelerate electron transfer during the reaction. At the same time, the interface between the two substances leaks more active sites, further accelerating electron transfer. Therefore, La2O2CO3/Co3O4 composites are expected to be widely used in solid propellants.

Keywords: La2O2CO3/Co3O4, Solution combustion, Interface, Thermal decomposition, AP/HTPB propellant.