Oxygen-Enriched Metal-Organic Frameworks Based on 1-(Trinitromethyl)-1H-1,2,4-Triazole-3-Carboxylic Acid and Their Thermal Decomposition and Effects on the Decomposition of Ammonium Perchlorate.

Abstract

Energetic metal-organic frameworks (EMOFs) with a high oxygen content are currently a hot spot in the field of energetic materials research. In this article, two series of EMOFs with different ligands were obtained by reacting 1-(trinitromethyl)-1H-1,2,4-triazole-3-carboxylic acid (tntrza) with metal iodide and metal nitrate, respectively. Furthermore, their structure, thermal stability, thermal decomposition kinetics, and energy performance are fully characterized. The research results revealed that the synthesized EMOFs possess a wide range of density (ρ = 1.88∼2.595 g cm-3), oxygen balance (OB(CO2) = -21.1∼ -4.3%), and acceptable energy performance (D = 7.73∼8.74 km s-1 and P = 28.1∼41.1 GPa). The difference in OB(CO2) caused by the ligand structure and metal properties has a great impact on the distribution of gas-phase products after the decomposition of these EMOFs. Noteworthy, [Ag(tntrza)]n is particularly prominent among these EMOFs, not only because of its excellent detonation performance (D = 8.74 km s-1 and P = 41.1 GPa) endowed by its extremely high density (ρ = 2.595 g cm-3) and oxygen balance (OB(CO2) = -4.3%) but also because of its effective catalytic effect on the decomposition of ammonium perchlorate (AP). This article broadens the horizon for the study of oxygen-enriched EMOFs with catalytic effects and helps understand the mechanism of thermal decomposition of EMOFs with nitroform and dinitro groups.