Use of perovskit catalysts in boron based solid rocket fuels

Rocket propellants are classified into two main categories: solid and liquid. Global rocket technologies and literature demonstrate that solid rocket propellants (SRPs) provide high thrust. Organizations such as NASA and ESA emphasize the critical role of SRP technology. Solid propellants offer higher thrust compared to liquid propellants but cannot be stopped once ignited. Liquid propellants, with their controllable combustion, are preferred for landings, while solid propellants are suitable for launch and orbital ascent. This study aims to utilize perovskite-structured catalysts to enhance combustion rate and stability in SRP formulations, replacing the conventional Fe2O3 catalyst, and to develop boron based SRP compositions using domestic boron resources as an alternative to aluminum. Catalysts were synthesized via the citrate-nitrate method, and their structural properties were analyzed using advanced characterization techniques. The crystal structure of the catalysts was determined by X-ray Diffraction (XRD), and their surface areas were measured using the Brunauer-Emmett-Teller (BET) method. Analyses confirmed that all catalysts formed the perovskite crystal phase and exhibited a porous morphology. The effects of the catalysts on the thermal decomposition behavior of ammonium perchlorate (AP) were evaluated using Thermogravimetric and Differential Thermal Analysis (TG/DTA) and isodönüşümal methods. The combustion performance of boron-based SRP compositions with added catalysts was tested in a closed combustion chamber under varying pressure conditions using a vertical-strand burner, and the burning rate was calculated. The catalysts successfully reduced the high decomposition temperature (HDS) of AP from 436 °C to 335.4 °C, 335.1 °C, and 343.1 °C, respectively. Additionally, the activation energy (Ea) of pure AP, determined as 142.8 kJ/mol in this project, was lowered to 101.1 kJ/mol, 82.4 kJ/mol, and 90.4 kJ/mol, respectively. Combustion videos recorded in slow-motion with a high-resolution digital camera were used to calculate burning rates. Graphs plotting the natural logarithm of pressure levels against these rates were analyzed using the Vieille equation, yielding pressure exponent (n) values within the desired literature range of 0.1–0.4. The n values for the selected catalysts were 0.30, 0.25, and 0.28, respectivelyAs a result of all the studies, compared to the combustion of pure boron containing CRY composition, La0.8Ca0.2Co0.5Mn0.5O3, La0.8Ca0.2Co0.5Fe0.5O3 and La0.8Ca0.2Co0.5Ni0.5O3 perovskite structured catalysts were able to reduce the combustion by approximately %15, %34 and %20, respectively.