仲钼酸铵热分解过程及热力学分析  

Thermal Decomposition of Ammonium Paramolybdate and its Thermodynamic Analysis

作　　者：周晓平 马琳 徐旭耀 冯宗财 

机构地区：[1]岭南师范学院化学科学与技术学院广东高校新材料工程技术开发中心物理化学研究所,广东湛江524048

出　　处：《稀有金属与硬质合金》2015年第3期25-28,共4页Rare Metals and Cemented Carbides

基　　金：国家星火计划资助项目(2012GA780015);湛江市科技攻关计划资助项目(2013B01033)

摘　　要：通过TG-DSC研究仲钼酸铵在空气气氛中及30~600℃温度范围内的热分解过程。结果表明:仲钼酸铵在30~600℃温度范围内的失重过程包含3个连续阶段,当温度高于340℃时,失重过程趋于结束。XRD测试结果证实热分解终产物为正交晶系MoO3纯相。提出了仲钼酸铵在空气气氛中的热分解机理并进行理论验证,认为仲钼酸铵的热分解过程除第一阶段单纯失去4个结晶水外,其余3个阶段均失去摩尔比为2∶1的NH3和H2O。同时还通过各阶段热分解反应的焓变值,估算了实验条件下仲钼酸铵及相关分解产物的近似标准摩尔生成焓。Thermal decomposition of ammonium paramolybdate in 30~600℃air was analyzed by TG-DSC.The results show that there are three stages during weight loss of ammonium paramolybdate at 30~600℃,and weight loss tends to finish when the temperature is higher than 340℃.XRD pattern shows that the end product of thermal decomposition is pure orthorhombic molybdenum trioxide.The mechanism of thermal decomposition of ammonium paramolybdate in the air was proposed and theoretical verification was carried out.It is considered that ammonium paramolybdate only loses four crystal water molecules in the first stage of its thermal decomposition,while NH3 and H2O are lost by the molar ratio of 2∶1in the other three stages.Otherwise,through enthalpy change values of decomposition reaction in the various stages,approximate molar formation enthalpy was estimated of ammonium paramolybdate and the related decomposition products under the experimental conditions.

关 键 词：仲钼酸铵 热分解 热重分析 差热分析 

分 类 号：TQ136.12[化学工程—无机化工]