Highly active catalysts based on 3D hierarchically ordered porous carbon with entrapped Fe_2O_3 nanoparticles for the thermal decomposition of ammonium perchlorate

摘要

Highly active catalyst with excellent ability to reduce the high-temperature decomposition (HTD) temperature and increase the apparent specific heat releases of ammonium perchlorate (AP) is an urgent requirement for the development of composite solid propellants. To this end, three-dimensional hierarchically ordered porous carbon (3D HOPC)/Fe2O3 composite scaffolds with high BET surface area (964-1697 m(2)/g) and large pore volume (1.40-2.36 cm(3)/g) are synthesized for higher catalytic activity. The entrapment of Fe2O3 nanoparticles (3.8-10.6 nm) inside 3D HOPC ensures their high dispersion and stability during the catalysis, and their size and content are readily tunable by adjusting the iron source concentration. The catalytic activity of HOPC/Fe2O3 composite scaffolds is investigated through synthesizing AP/HOPC/Fe2O3 nanocomposites, in which AP nano crystals are homogeneously confined. Owing to the synergistic effect between 3D HOPC and Fe2O3 nano particles, HOPC/Fe2O3 composite scaffolds exhibit outstanding catalytic activity for AP thermal decomposition in decreasing the HTD peak temperature from 440.9 to 280.5 degrees C, lowering the activation energy from 176.4 to 132.2 kJ/mol, and increasing the heat release from 371 to 2114 J/g. This work constructs a highly active catalyst configuration by entrapping nano transition metal oxides inside carbon scaffolds, which has broad application prospects in AP-based composite solid propellants.