Unveiling the unprecedented catalytic capability of micro-sized Co-ZIF-L for the thermal decomposition of RDX by 2D-structure-induced mechanism reversal† † Electronic supplementary information (ESI) available: Experimental section, SEM images, FT-IR spectra, XPS spectra, TG-DTG curves, DSC curves, MS curves, crystal structure, micropore size distribution curve, free energy for different decomposition pathways and Tables S1 and S2. See DOI: https://doi.org/10.1039/d3ra01551c

ABSTRACT: Developing MOF-based catalysts with superior catalytic properties for the thermal decomposition of cyclotrimethylenetrinitramine (RDX) is significant for the application of novel and efficient combustion catalysts oriented to RDX-based propellants with excellent combustion performance. Herein, micro-sized Co-ZIF-L with a star-like morphology (SL-Co-ZIF-L) was found to exhibit unprecedented catalytic capability for the decomposition of RDX, which can lower the decomposition temperature of RDX by 42.9 °C and boost the heat release by 50.8%, superior to that of all the ever-reported MOFs and even ZIF-67, which has similar chemical composition but a much smaller size. In-depth mechanism study from both experimental and theoretical views reveals that the weekly interacted 2D layered structure of SL-Co-ZIF-L could activate the exothermic C–N fission pathway for the decomposition of RDX in the condensed phase, thus reversing the commonly advantageous N–N fission pathway and promoting the decomposition process in the low-temperature stage. Our study reveals the unusually superior catalytic capability of micro-sized MOF catalysts and sheds light on the rational structure design of catalysts used in micromolecule transformation reactions, typically the thermal decomposition of energetic materials. 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.

SUBMITTER: Ren J 

PROVIDER: S-EPMC10123532 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature