N2O Decomposition on Ru/Si-doped Alumina Catalyst for Monopropellant Thruster

In the present study, ruthenium (Ru) catalysts supported on silicon-doped alumina (Si-Al 2 O 3 ) were prepared and catalytic decomposition of nitrous oxide (N 2 O) on the Ru/Si-Al 2 O 3 catalyst at high temperatures were investigated.The Si-Al 2 O 3 was heat-treated at a high temperature of 1200C.The effect of Si addition on Al 2 O 3 surface structure was investigated using SEM/EDS and XRD analysis.The N 2 O decomposition on the prepared catalysts was evaluated as the reaction temperature increased.It was shown that Si addition prevented the -Al 2 O 3 phase transforming to -Al 2 O 3 .The Ru/Si-Al 2 O 3 catalyst showed a superior reactivity for the N 2 O decomposition.A subscale N 2 O monopropellant thruster containing the Ru/Si-Al 2 O 3 catalyst chamber was manufactured.The temperature of 300C was required to start N 2 O decomposition.The chamber temperature increased to 1063C at N 2 O mass flow rate of 1.93 g/s.The chamber pressure was 5 bar at 1063C; thus, the c*-efficiency was calculated as 89.05%.