Study of Preparation of Nano Nd_xCo_(2-x)Zr_2O_7 and its Catalytic properties on ammonium perchlorate thermal decomposition

摘要

Cubic pyrochlore type Nd_xCo_(2-x)Zr_2O_7 nano-crystals were prepared by salt-assistant glycine solution combustion method (SGCM), with neodymium nitrate, cobalt nitrate and zirconium nitrate as raw materials, glycine as the incendiary agent, and KCl as a reaction inert salt. The Nd_xCo_(2-x)Zr_2O_7 nano-crystals were characterized by means of XRD (X-ray powder diffraction), FT-IR (Fourier transform- infrared spectroscopy), Raman spectroscopy, TEM (Transmission electron microscope) and HRTEM (High resolution transmission electron microscopy). The results showed that neodymium ions were partially substituted by cobalt ions, while maintaining the original pyrochlore structure. The nano particles obtained had a perfect crystal structure, good dispersion, and the size was about 31 nm. For Nd_(1.9)Co_(0.1)Zr_2O_7 nanocrystals, the four strong diffraction peaks were at 2θ=29.18°, 33.80°, 48.49°and 57.53°. The corresponding crystal plane distances calculated by Bragg equation λ=2dSinθ were 0.306, 0.265, 0.188 and 0.160 nm. Study the catalyst effect of Nd_xCo_(2-x)Zr_2O_7 on the thermal decomposition of ammonium perchlorate (AP) using DSC (Differential scanning calorimetry). The results showed that nano Nd_xCo_(2-x)Zr_2O_7 had high catalytic activity during on the thermal decomposition of ammonium perchlorate. With 2% more nano Nd_xCo_(2-x)Zr_2O_7, the peak temperature of AP thermal decomposition reaction dropped by nearly 88°C. The apparent decomposition reaction heat increased from 655 J·g~(-1) to 1073 J·g~(-1). The results showed that the catalytic effect of thermal decomposition of AP with nano cobalt-doped zirconium acid neodymium is better than the single component of nano-metal oxides and undoped zirconate neodymium nanocrystals.