磷酸钴铵的合成及热分解动力学研究

以CoCl2.6H2O和(NH4)3PO4.3H2O为原料,在适量表面活性剂聚乙二醇-400的存在下,先在室温下研磨反应混合物进行固相反应,然后将反应混合物在80℃下保温陈化4h,接着用水洗去混合物中可溶性的无机盐,然后在110℃下烘干2h,得到(NH4)3CoPO4.H2O晶体材料。用XRD,IR,SEM及TG/DTA对产物进行表征。采用热重差热法(TG/DTA)分析研究该产物的热分解过程。结果表明,(NH4)3CoPO4.H2O在105～800℃有2个显著的失重平台,这2个失重过程机理函数所对应的活化能、频率因子(LnA)及热分解机理机理函数分别为:(a)E=97.83kJ/mol,lnA=23.26s-1,ln(1-a)];(b)E=87.36kJ/mol,lnA=15.60s-1,1-(1-a)1/2。

Synthesis and Characterization of Ammonium Cobalt Phosphate Hydrate via A Low-Heating Solid-State Reaction

The crystalline （NH4）3COPO4 · H2O was prepared in the presence of surfactant PEG -400 with fully grinding COCl2 · 6H2O and （NH4）3PO4 · 3H2O as raw materials by a solidstate at room temperature. The reaction mixtures were aged at 80℃ for 4h, then washed with water to remove soluble inorganic salts and dried at 110℃ for 2h to obtain the crystals of （NH4）3CoPO4 · H2O. The products were characterized with XRD, IR,SEM and TG/DTA. The thermal decomposition kinetics of α-LiZnPO4 · H2O was studied by thermo-gravimetric- differential thermal analysis（TG-DTA）. The results showed that the thermal decomposition of the （NH4）3CoPO4 · H2O was carred in two well-defined weight loss processes. The activa- tionenergy（E）,frequency factor（lnA） and mechanism functiong（α）]for the two processes are： （a） E= 97. 83kJ/mol,lnA =23. 26 s^-1,-ln（1-a）];（b）E=87.36kJ/mol,lnA =15.60 s^-1,1- （1-a）^1/2 .