Research on catalytic performance of transition-metal-based MOFs towards thermal decomposition of RDX

Abstract

It is beneficial for the efficient energy utilization of propellants to develop high - efficiency catalysts for thermal decomposition of energetic materials. Herein, catalytic characteristics of different transition-metal-based MOFs on thermal decomposition of cyclotrimethylenetriamine (RDX) were studied, such as [Zn2(atz)3(N3)]n, MIL-88B and ZIF-67. ZIF-67 was found to exhibit superior properties therein. On this basis, size effect of ZIF-67 when catalyzing the thermal decomposition of RDX was further investigated. It has been found that the catalytic performance can be boosted as the size of ZIF-67 is reduced. However, the performance will decline when the size is ulteriorly reduced into nanoscale. Besides, the doping of Ni, Cu or Zn into ZIF-67 has little effect on the promotion of the catalytic performance. Among all the catalysts, ZIF-67-S shows the best catalytic performance for the thermal decomposition of RDX, which is superior to most existing catalysts. Specifically, it can reduce the thermal decomposition peak temperature of RDX by 22.4 °C and enhance the apparent decomposition heat by 59.9%. As a consequence, it is expected to be used as a combustion catalyst in propellants such as 3D printing gun propellants with high RDX contents.