Lanthanum Hexaaluminate Catalyst Support in a Hydrogen Peroxide Thruster

摘要

A catalyst performance of manganese dioxide with lanthanum hexaaluminate as catalyst support was experimentally investigated in the 10 N scale thruster environment. Rocket-grade hydrogen peroxide was used as the propellant. The compression and the heating tests of the LHA were also conducted to examine mechanical and thermal performances. Comparison has been made with the gamma-alumina catalyst support. From the compression tests, it was found that the mass loss rate for the γ-Al_2O_3 was higher than that of the LHA by about four to eight times, indicating better durability of the LHA. From the heating tests, the LHA was shown to preserve a higher BET surface area and pore properties than that of the γ-Al_2O_3, implying thermally better resistibility at high temperatures. From the thruster tests, because of the better durability and thermal resistance of the MnO_2/LHA, more stable temperature and pressure profiles were observed on the catalyst bed than the MnO_2/γ-Al_2O_3 case. It was exhibited that the LHA support had greater strength and high-temperature survivability with significantly less mass loss. Moreover, it was verified that the decomposition performance, as well as the durability and the thermal resistance, could be improved, depending on the transition metal added on the catalyst. In this study, it was found that the MnO_2/LHA catalyst was more appropriate for the 98 wt% RGHP monopropellant thruster than the MnO_2/γ-Al_2O_3.