溴酸钾非等温热分解过程及热分解动力学研究  

Study on Non-isothermal Decomposition and Thermal Decomposition Kinetics of Potassium Bromate

作　　者：欧阳刚 张金进 刘韦光 梁峻 刘柏清 OUYANG Gang;ZHANG Jin-jin;LIU Wei-guang;LIANG Jun;LIU Bo-qing(Guangzhou Academy of Special Equipment Inspection&Testing,Guangzhou 510180,China;China National Quality Supervision and Testing Center of Explosion-proof Equipment(Guangdong),Guangzhou 510180,China)

机构地区：[1]广州特种机电设备检测研究院,广州510180 [2]国家防爆设备质量监督检验中心(广东),广州510180

出　　处：《当代化工》2021年第9期2041-2045,共5页Contemporary Chemical Industry

基　　金：国家重点研发计划项目(项目编号:2018YFC0808904)。

摘　　要：为了解溴酸钾(KBrO_(3))的热性能,利用差热分析(DTA)研究了KBrO_(3)的非等温热分解过程。采用Kissinger法和Ozawa法计算了KBrO_(3)的热力学参数,并与硝酸铵(NH_(4)NO_(3))的热稳定性进行了对比。结果发现:KBrO_(3)在400℃附近开始熔化,随后发生放热分解,其热分解是分两个阶段进行的,在升温速率为5℃×min^(-1)时,第一阶段的放热峰温为432.28℃,第二阶段的放热峰温为439.86℃;第一阶段热分解活化能E、焓变△H^(≠)、熵变△S^(≠)及吉布斯自由能△G^(≠)分别为175.17 kJ×mol^(-1)、169.15 kJ×mol^(-1)、-25.32 kJ×K^(-1)∙mol^(-1)和187.51 kJ×mol^(-1);对比KBrO_(3)两阶段热分解的熵变△S^(≠),发现第二阶段热分解比第一阶段热分解更易发生;KBrO_(3)的热稳定性优于硝酸铵(NH_(4)NO_(3))。Non-isothermal decomposition of potassium bromate(KBrO_(3))was researched to understand the KBrO_(3)thermal properties by differential thermal analysis(DTA).The Kissinger and Ozawa methods were used to calculate the thermodynamic parameter of E,△H^(≠),△S^(≠)and△G^(≠),and the thermal stability of KBrO_(3)was compared with that of the ammonium nitrate(NH_(4)NO_(3)).It was found that the KBrO_(3)began to melt around 400℃,and then exothermic decomposition occurred.The thermal decomposition could be divided into two stages.When the heating rate was 5℃×min^(-1),the exothermic peak temperature of the first stage and second stage were 432.28℃and 439.86℃separately;Moreover the first stage thermal decomposition activation energy E,enthalpy change(35),entropy change(35)and Gibbs free energy(35)were 175.17 kJ×mol^(-1),169.15 kJ×mol^(-1),-25.32 kJ×K^(-1)·mol^(-1),187.51 kJ×mol^(-1)respectively.Comparing the entropy change of the two stage thermal decomposition of KBrO_(3),it was concluded that the second stage thermal decomposition was more likely to occur than the first stage thermal decomposition.

关 键 词：KBrO_(3) DTA 热分解 热力学参数 

分 类 号：X931[环境科学与工程—安全科学]