MgH2的制备及对高氯酸铵热分解过程的影响

Synthesis of Magnesium Hydride and Its Effect on Thermal Decomposition of AP

摘要:

采用直接氢化法制备氢化镁（MgH2），运用XRD、SEM、ICP等方法对其结构进行表征。用热分析法（DSC）研究氢化镁对高氯酸铵（AP）热分解过程的影响。结果表明，5%MgH2可分别使AP的低温和高温放热分解峰温降低35.0和44.2 ℃，使AP的DSC表观分解热由0.44增加到1.20 kJ·g-1，表现出对AP热分解过程具有显著的增强促进作用。随着加入量增加，氢化镁对AP热分解的催化促进作用逐渐增强，但当氢化镁含量达到30%时，催化促进作用开始下降。氢化镁对AP热分解的催化促进作用明显强于纯镁粉。探讨了氢化镁增强促进AP热分解过程的作用机制。

Abstract:

Magnesium hydride (MgH2) was synthesized by a direct-hydriding method, and its structure was characterized by XRD, SEM and ICP. The thermal decomposition behavior of ammonium perchlorate (AP) in the presence of MgH2 was investigated by DSC. Results show that 5% MgH2 can decrease low-temperature and high-temperature thermal-decomposition peak-temperatures of AP by 35.0 oC and 44.2 oC respectively, and increase the DSC apparent heat release of AP from 0.44 kJ·g-1 to 1.20 kJ·g-1, which indicates that MgH2 has a remarkable catalytic effect on AP thermal decomposition. The catalytic effect of MgH2 was enhanced gradually with increasing of MgH2 content. However, the effect went down when the MgH2 content reached 30%. The catalytic effect of MgH2 on the thermal decomposition of AP was obviously better than that of pure magnesium powder. The mechanism of MgH2 for catalyzing the thermal decomposition of AP was also studied.