Metal bistetrazolates as catalysts for ammonium perchlorate decomposition and combustion

摘要

Ammonium perchlorate (AP) is widely used as an oxidizer in energetic systems, and the possibility to tailor its reaction rate and decomposition temperature by the catalyst addition is crucial for obtaining the desired parameters of AP-fuel mixtures. Metal bistetrazolates comprise the high-nitrogen containing tetrazole anion with the metal cation. During the decomposition of these salts metal particles are expected to be formed, being, according to the literature, the effective catalytic agents for AP. Here we explore catalytic abilities of bistetrazole compositions with different metals, viz., Cu, Ni, and Mn. Thermal analysis study reveals the shift of the AP exothermic high-temperature decomposition peak to the lower temperatures, proving the catalytic activity of all the investigated metal bistetrazolates. However, the burning rate of ammonium perchlorate monopropellant with 5% addition of various metal bistetrazolates is more complex and exhibits the increase for copper bistetrazolates only, which enhances the burning rate in more than 3 times within 2-10 MPa pressure range. On the contrary, manganese bistetrazolate even decreases the AP burning rate, apparently due to the crystallized water within the molecule. The results show that the combination of the high-nitrogen containing molecular structure with the copper cation can be successfully used as combustion catalyst for AP-fuel formulations.