Performance and deactivation of Ir/γ-Al 2O 3 catalyst in the hydrogen peroxide monopropellant thruster

Abstract

The performance of Ir/γ-Al 2O 3 catalyst for the decomposition of high concentration hydrogen peroxide was investigated in a monopropellant thruster. The changes of ignition delay ( t 0), chamber pressure ( P c) and catalyst bed temperature ( T c) with the numbers of startup–shutdown cycles were proved to be effective indicators of catalyst bed efficiency. The fresh catalyst and the deactivated catalyst were characterized with H 2-TPR, XRD and XPS. It was found that catalyst oxidation and surface Sn poisoning are the major reasons of catalyst deactivation.