Enhanced catalytic activity and ignition characteristics of three-dimensional ordered macroporous FeCo2O4 through controlled synthesis

Abstract

To improve the combustion performance of solid propellants relies on efficient combustion catalyst with large specific surface area and high density of active sites. In this work, three-dimensional ordered macroporous FeCo2O4 (3DOM-FeCo2O4) with four different pore diameters was successfully prepared using polymethyl methacrylate (PMMA) colloidal crystals as a template. Differential scanning calorimetry (DSC) study shows that 3DOM-FeCo2O4 with a pore diameter of 176 nm has the best catalytic performance on the thermolysis of ammonium perchlorate (AP). The decomposition peak temperature and apparent activation energy were reduced by 116.5 ℃ and 26.1 kJ/mol, respectively. Thermogravimetry/mass spectrometry (TG/MS) was used to analyze the catalytic mechanism. The result indicates that 3DOM-FeCo2O4 can accelerate the electron transfer from ClO4– to NH4+ to form HClO4 and NH3 and the transformation from O2 to superoxide ion(O2–), thus providing active sites for intermediate products of AP and catalyzing the decomposition of AP. Furthermore, the heat release and ignition tests of thermites using 3DOM-FeCo2O4 as the oxidant were carried out. The thermite with a pore diameter of 215 nm exhibits higher heat release and better ignition characteristic compared to the thermites with other pore diameters.