Effect of dual-catalytic bed using two different catalyst sizes for hydrogen peroxide thruster

For a catalytic bed in hydrogen peroxide based propulsion systems, a high pressure drop can cause significant problems. Hence, a dual-catalytic bed was suggested to reduce the pressure drop across the catalytic bed. Catalysts of two different sizes (1/8 inch, and 1.18-2.00 mm) were employed, which were fabricated using an impregnation method with MnO2 and PbO as the active materials. The upstream and downstream sides of the dual-catalytic bed were loaded with the catalyst with dimensions of 1.18-2.00 mm and 1/8 inch, respectively. The effectiveness of the dual-catalytic bed was verified by conducting hot-fire tests with hydrogen peroxide monopropellant mode. The trends in the pressure drop across the catalytic bed and the characteristic velocity efficiency were investigated with respect to the mass flux and mass ratio of the loaded catalysts. As the mass ratio of the smaller catalyst was reduced to 18.3%, the pressure drop constantly decreased with an identical mass flux, though most of the fed hydrogen peroxide was still fully decomposed.