The unprecedented catalytic performance of micro-sized Co-ZIF-L for the decomposition of RDX was deeply explored and reveals its 2D-structure-induced ability to reverse the commonly advantageous N–N fission pathway in the low-temperature stage.

Developing delicate methods to synthesize well-controlled nanostructures is diffusely recognized as a potent tool to enhance photocatalysts’ performances in various photoreactions. Herein, phase-controlled CdS hierarchical nanostructures were synthesized using a MOF-templated strategy, where Co-MOF nanospheres were used as the starting material, followed by two steps of sulfidation and cation exchange. By rational collocations of the solvent and Cd source in the cation exchange process, cubic CdS hollow hierarchical nanospheres and hexagonal CdS hierarchical nanostructures can be obtained, respectively. Further tests revealed that during the photo-reduction reaction of CO2, the former exhibited high performance in producing H2. At the same time, the latter showed a superior activity and selectivity for CO generation, which embodies the potential of MOF-templated synthesis and selective applications of CdS hierarchical nanostructures with disparate phases.

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.