Bimetallic MOF (Mn/Co) constructed by active dicyandiamide linker for a promising combustion catalyst of solid propellant

Combustion catalyst is a key modifier for the performance of composite solid propellant. To exploit high-efficiency combustion catalyst, a fascinating bimetallic metal-organic framework [MnCo(EIM) 2 (DCA) 2 ] n (1) was constructed by an active dicyandiamide (DCA) linker, Mn 2+ , Co 2+ centers, and an 1-ethylimidazole (EIM) ligand. 1 possesses good thermal stability ( T p = 205 °C), high energy density ( E g = 24.34 kJ/g, E v = 35.93 kJ/cm 3 ), and insensitivity to impact and frictional stimulus. The catalytic effects of 1 contrasted to monometallic coordination compounds Mn(EIM) 4 (DCA) 2 (2) and Co(EIM) 4 (DCA) 2 (3) on the thermal decomposition of AP/RDX composite were investigated by a DSC method. The decomposition peak temperatures of AP and RDX of the composite decreased to 335.8 °C and 206.4 °C, respectively, and the corresponding activation energy decreased by 27.3% and 43.6%, respectively, which are better than the performances of monometallic complexes 2 and 3. The gas products in the whole thermal decomposition stage of the sample were measured by TG-MS and TG-IR, and the catalytic mechanism of 1 to AP/RDX was further analyzed. This work reveal potential application of bimetallic MOFs in the composite solid propellants. • The second metal and highly active anion DCA were introduced into the combustion catalyst. • DCA assembles energetic ligands and metal centers to prepare novel energetic MOF. • MOF can greatly reduce the decomposition temperature and activation energy of AP and RDX at the same time. • The action mechanism of MOF on AP and RDX was revealed.