Hydrazine monopropellant is often used with a spontaneous catalyst a high-performance aircraft emergency power unit (EPU) and in aerospace propulsion; however, it is toxic and requires special handling. A hydrogen peroxide (H2O2)-based gas generator, which is suitable for a new family of environmentally friendly monopropellants and is a substitute for toxic hydrazine in EPUs, is introduced in this study. A MnO2/Al2O3 catalyst for H2O2 decomposition, superior to silver catalysts at normal starting and reactivity capabilities, was selected and developed. The performance tests of coupling the gas generator with a turbocharger showed acceptable results for an aircraft EPU with decomposition above 90%, 37 kW maximum turbine output power, and a maximum starting delay of 1.2 s during normal starting operation. The gas generator also demonstrated satisfactory performance during repeated pulse operation at a pulse duration of 3 s and 60 s under various output conditions.