高铁酸钾热分解的研究

A STUDY OF THE THERMAL DECOMPOSITION OFK_2FeO_4

本文采用差热热重仪、穆斯堡尔谱仪、X射线光电子能谱仪和X射线衍射仪等分析仪器,研究了高铁酸钾的热分解过程,提出热分解产物可能形成固熔体的看法。

The thermal decomposition process of a hexavalent iron compound, K2FeO4, was studied by means of the thermogravimetrical and differential thermoanalytical techniques, Mossbauer spectroscopy and X-ray diffraction technique.The sample was confirmed to be a single phase of K 2FeO4 by the X-ray diffraction technique. The compound began to decompose in air at about 310℃. The intermediate valence states, Fe5+ or Fe4+, were not observed during the decomposition process.So it was concluded that Fe6+ ions in K2FeO4 were directly reduced to Fe3+ ions in KFeO2. The product formed solid solution compound, which continued to decompose in air at 680℃, firming K2O·2KFeO2. The product showed a paramagnetic Mossbauer spectrum at 400℃ with an isomer shift and quadrupolc splitting of-0.016 mm / s and 0.023mm / s respectively. The binging energy of OlT, Fe and K in both the sample and product have been measured and discussed.The decomposition process may be expressed by the equation: 2K2FeO4→K2O·2KFeO2+O2 (-310℃) K2O2·2KFeO2→K2O·2KFeO2+1/2O2 (>680℃)