Ordered Mesoporous Cu-Mn Metal Oxides for the Catalytic Decomposition of an Energetic Ionic Liquid.

Abstract

Ordered mesoporous Cu-Mn binary metal oxide (meso-CuMnOx) catalysts were successfully synthesized by a hard-templating method from a mesoporous silica template with a cubic Ia3d mesostructure (KIT-6) or hydrophobic KIT-6, exhibiting a well-developed crystalline framework, a regular pore size distribution and a high surface area. The copper and manganese elements in the mesoporous Cu-Mn binary metal oxides (meso-CuMnOx-N and meso-CuMnOx-HP), obtained from the KIT-6 and hydrophobic KIT-6, respectively, were homogeneously dispersed in the whole particles. The activities of meso-CuMnOx catalysts for the decomposition of a liquid monopropellant containing an energetic ionic liquid, ammonium dinitramide, were much higher than that over a CuMnOx catalyst prepared by a conventional precipitation method. This is attributed to the well-developed mesoporosity of the meso-CuMnOx catalysts. Among the mesoporous CuMnOx catalysts, the decomposition onset temperature over meso-CuMnOx-HP (87.9 °C) was found to be lower than that over meso-CuMnOx-N (100.4 °C), probably due to its higher mesoporosity and surface area.