Department of Chemistry, Science Institute, North University of China, Taiyuan, Shanxi 030051, PR China.
J Hazard Mater. 2010 May 15;177(1-3):554-9. doi: 10.1016/j.jhazmat.2009.12.068. Epub 2009 Dec 22.
Perovskite-type LaMnO(3) and La(0.8)Sr(0.2)MnO(3) with high specific surface areas were prepared by stearic acid gel combustion method. The obtained powders were characterized by XRD, FT-IR, SEM and XPS techniques. Their catalytic activities were investigated on thermal decomposition of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by TG-DSC techniques. The experimental results show that LaMnO(3) is a more effective catalyst than La(0.8)Sr(0.2)MnO(3) for the sublimation and melting process of RDX because of its higher concentration ratio of surface-adsorbed species. And the catalytic activity of La(0.8)Sr(0.2)MnO(3) is higher than that of LaMnO(3) for thermal decomposition of liquid RDX. This could be attributed to its higher concentration ratios of surface oxygen and Mn(4+)/Mn(3+). In conclusion, the concentration ratios of surface oxygen and Mn(4+)/Mn(3+) could play key roles for RDX thermal decomposition. This study points out a potential way to develop new and more active perovskite-type catalysts for the RDX thermal decomposition.
采用硬脂酸凝胶燃烧法制备了具有高比表面积的钙钛矿型 LaMnO(3)和 La(0.8)Sr(0.2)MnO(3)。采用 XRD、FT-IR、SEM 和 XPS 技术对所得粉末进行了表征。通过 TG-DSC 技术研究了它们在六氢-1,3,5-三硝基-1,3,5-三嗪 (RDX) 热分解中的催化活性。实验结果表明，由于表面吸附物种的浓度比更高，LaMnO(3)对于 RDX 的升华和熔化过程是一种比 La(0.8)Sr(0.2)MnO(3)更有效的催化剂。而 La(0.8)Sr(0.2)MnO(3)对于液态 RDX 的热分解的催化活性高于 LaMnO(3)。这可以归因于其表面氧和 Mn(4+)/Mn(3+)的浓度比更高。总之，表面氧和 Mn(4+)/Mn(3+)的浓度比可能对 RDX 的热分解起着关键作用。本研究为开发新型、更有效的钙钛矿型 RDX 热分解催化剂指出了一条潜在途径。
