Preparation, characterization, and catalytic activity of rare earth metal oxide nanoparticles

In present study, a series of rare earth metal oxide (CeO₂, Pr₂O₃, and Nd₂O₃) nanoparticles have been prepared by sol–gel route using Ce(NO₃)₃·6H₂O, Pr(NO₃)₃·6H₂O and Nd(NO₃)₃·6H₂O, and citric acid as precursor materials. Powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy are employed to characterize the size and morphology of the nano oxide particles. The particles are spherical in shape and the average particle size is of the order of 11–30 nm. Their catalytic activity was measured on the thermal decomposition of ammonium perchlorate and composite solid propellants (CSPs) by thermogravimetry (TG), TG coupled with differential thermal analysis (TG–DTA), and ignition delay measurements. The ignition delays and activation energies are found to decrease when rare earth metal oxide nanoparticles were incorporated in the system. Addition of metal oxide nanoparticles to AP led to shifting of the high temperature decomposition peak toward lower temperature and the burning rate of CSPs was also found to enhance. However, E _a activation energy for decomposition was also found to decrease with each catalyst.