摘要
用热重分析(TG),差热分析(DTA),傅里叶红外光谱分析(FTIR)和X射线衍射(XRD)等方法研究了Nd(C2H5CO2)3.H2O的热分解性质。在流动的Ar气中加热到1200℃,水合丙酸钕的分解可以分成6个步骤。在经过脱水反应之后,Nd(C2H5CO2)3首先在250℃和292℃之间生成Nd2(C2H5CO2)4.CO3并释放出二乙基甲酮。当温度升高到315℃,伴随着CO2气体的放出,Nd(C2H5CO2)3立即分解成Nd2O(C2H5CO2)4。在424℃之前,伴随着二乙基甲酮和CO2气体产生,Nd2O(C2H5CO2)4首先分解成中间相Nd2O(CO3)2,并立即转化成分解产物Nd2O2CO3。随着温度升高到770℃,含Nd化合物完全转化成Nd2O3。研究表明,Nd(C2H5CO2)3.H2O在空气中的TG曲线和其在Ar气中的没有任何改变。但是,分解产物二乙基甲酮气体在空气中的燃烧会产生很强的放热效应。与其它稀土金属丙酸盐的热分解的研究结果比较而言,Nd(C2H5CO2)3.H2O的分解性质表现出一些有趣的特点。特别是,在其它丙酸盐中没有发现类似中间相Nd2(C2H5CO2)4.CO3的生成的情况。
The thermal decomposition of Neodymium（Ill） propionate hydrate （Nd（C2H5CO2）3·H2O） has been investigated using thermogravimetry and differential thermal analysis, together with infrared spectroscopy and X-ray diffraction. Upon heating to 1200℃ in flowing argon, Nd propionate hydrate decomposes in seven steps. After dehydration, which takes place around 95 ℃, anhydrous Nd propionate firstly decomposes to Nd2（C2H5CO2）4-CO3 by releasing 3-pentanone between 250 ℃and 292 ℃. The Nd2（C2H5CO2）4·CO3 immediately decomposes to yield Nd2o（C2H5CO2）4 up to 315 ℃ and this step is characterized by CO： evolution. The conversion of Nd2O （C2H5CO2）4 to Nd2o2CO3 proceeds up to 424 ℃ in two steps involving a Nd20 （CO3）2 intermediate. 3-pentanone and CO2 respectively evolve during these steps. Full conversion ofNd propionate to Nd2O3 is completed at 770 ℃. This decomposition scheme is not modified if air is used instead of Ar but the released 3-pentanone undergoes combustion resulting in strong exothermic effects. Compared with previous studies on rare-earth propionates, the thermal decomposition behaviour of Nd （C2H5CO2）3·H2O exhibits some interesting differences. In particular, there is an intermediate stage consisting in the formation of Nd2（C2H5CO2）4·CO3, which is not found in the case of the other propionates reported up to now.
出处
《广东化工》
CAS
2013年第6期52-54,51,共4页
Guangdong Chemical Industry
