Green synthesis and catalytic activity assessment of bespoke nano-catalyst for eco-friendly green propellant systems based on hydrogen peroxide

Abstract

Much effort has been devoted to replace pollutant, toxic, cancerogenic hydrazine-based propellants. Hydrogen peroxide could secure promising characteristics as well as high density specific impulse. Effective catalysts with high durability are required to commence H2O2 decompositions, and to inherit hypergolic nature with different hydrocarbon fuels. Silver nanoparticles (18 nm) were synthesized via hydrogen gas evolved by water electrolysis. MnO2 (20 nm) was developed in a sustainable manner via green hydrothermal processing. High crystalline, mono-dispersed particles were developed. Catalytic activity was assessed via precise measurements of liquid temperature profile (LTP) up to the boiling point of hydrogen peroxide. Whereas silver demonstrated LTP peak within 20 s; MnO2 experienced LTP within 40 s. Catalyst survivability was recorded via precise measurement of life time mass loss rate upon catalyst addition to hydrogen peroxide. While silver nano-catalyst demonstrated high performance at the reaction start; silver was found to be poisoned with crystalline phase change to silver oxide within 20 s. On the contrary, manganese oxide experienced high durable catalytic action. Consequently, MnO2 could be candidate for H2O2 monopropellant thrusters as catalyst bed. On the other hand, silver nanoparticles could be candidate for a single use in bipropellant system to inherit hypergolicity. This study presents a pioneering report on facile synthesis of catalyst nanoparticles; comprehensive catalytic activity assessment of silver to manganese oxide for H2O2 decomposition was represented. Proper catalyst assortment for practical applications was represented.