Preparation Of Graphene-supported Cu And Cu/Co Catalysts And Their Catalytic Thermal Decomposition Of AP

Ammonium perchlorate(AP)is the most common oxidizer in solid fuel rocket composite solid propellants,accounting for 60-90% of the total propellant weight.Therefore,the thermal decomposition characteristics of AP will directly affect the combustion behavior of solid propellant.However,high decomposition temperature,staged decomposition(high and low temperature decomposition process)and low exothermic concentration of AP,which lead to slow decomposition and incomplete decomposition.Adding catalyst is an effective way to improve the thermal decomposition property process of AP.In this paper,graphene supported Cu and Cu/Co catalysts were prepared with MOF as the precursor and GO as the carrier,and the above catalysts were successfully combined with AP by spray drying method.DSC experiment was used to study the effect of spray recombination and mechanical mixing on the thermal decomposition performance of AP.The specific research contents are as follows:Graphene-supported Cu clusters catalysts were successfully prepared using a combination of solvothermal and heat treatment in which transition metal ions are bonded to the GO surface by organic ligands.Two-dimensional graphene-supported Cu catalyst was obtained after heat treatment.The effect of the morphology and structure of the catalyst on the decomposition of AP at different temperatures was studied.The results showed that the particle size of the catalyst was 20 nm at 300 ? and uniformly distributed on r GO.When the mass ratio of GO/Cu-MOF-300 to AP was 5:95,the catalyst promoted the decomposition temperature of AP by 73.7 ?,and the heat release of AP increased from 652.73 J/g to 1392.11J/g.The activation energy of AP decomposition at high temperature decreased from 202.17 k J/mol to 154.82 k J/mol.GO/Cu-MOF-300 inactivated the low temperature decomposition process of AP,but catalyzed the high temperature decomposition process of AP,and improved the thermal stability of AP.Graphene-supported Cu/Co catalysts were obtained by solvothermal and heat treatment of metal salts containing cobalt and copper,respectively.The structural components were analyzed by SEM,TEM,XRD,XPS and other characterization methods,and the catalytic thermal decomposition of AP was studied by DSC test.The results showed that the GO/Cu/Co-MOF-650 catalyst with particle size of 10?20 nm was obtained after two hours of treatment at 650 ?.The catalyst reduced the decomposition temperature of AP at high temperature by 99.5 ?,but increased the decomposition temperature at low temperature by21.37 ?.More importantly,compared with pure AP,the heat release increased from 587.46J/g to 1287.45 J/g,which more than doubled,and the activation energy decreased from 197.24 k J /mol to 159.63 k J /mol,showing excellent catalytic capacity for AP.Under the effective coordination of GO,metal oxides and metal nanoparticles,the electron transfer in the high temperature decomposition stage of AP is accelerated and the thermal decomposition capacity of AP is improved.By changing the bonding mode of catalyst and AP,mechanical mixing and spray compounding were used according to a certain mass ratio,respectively,and the influence of different methods on AP thermal decomposition catalytic performance was discussed.The experimental results show that at the heating rate of 5 K/min,the high temperature decomposition temperature of the GO/Cu/Co-MOF-650 catalyst and AP composite formed by spray is 18.4 ? earlier than that of mechanical mixing,which also proves that the catalyst has a better thermal decomposition catalytic capacity for AP when the contact area between the catalyst and AP is larger and more uniform.