Additively Manufactured Reactor For High Performance, Non-Toxic Monopropellants

This proposal focuses on manufacturing and testing of high-performance, high-quality, and low-cost additively manufactured reactor catalyst beds for use in thrusters. Catalyst reactor beds must vaporize water and catalyze the propellant constituents in temperatures ranging from 300 °C to 1850 °C without losing structural stability or catalytic reactivity due to sintering, attrition, or depletion of active materials. Current state of the art catalysts are commonly made from granular ceramic carriers that are impregnated with various platinum group metals to increase activity. Ceramic beds do not have the necessary structural strength at high temperatures and will sinter rapidly above 1550 °C. Over time, sintering generates voids inside the bed which often result in negative effects such as increased thrust roughness, channeling of propellant through the bed, and repacking of the bed. These effects may result in the loss of the thruster or severely limiting the lifetime of the propulsion system. Additively manufactured, monolithic metallic foam catalyst reactor beds can replace granules for green monopropellant thrusters. High temperature materials and innovative designs will provide game changing results on various size thrusters currently in development. The proposed research will enable lower-cost, more robust, and longer life monopropellant propulsion systems using new catalyst beds.