Studies on thermal stabilities of coordination compounds by gas chromatography: XX. The solid state reaction of sodium nitrate and iron (III) oxalate in hydrogen atmosphere

The solid state reaction of sodium nitrate and iron (III) oxalate in hydrogen atmosphere was investigated by gas chromatography, Mossbauer spectroscopy and X-ray diffraction. The results show that there is no reaction below 240°C between them while iron (III) Oxalate decomposes itself into α-FeC2O4 and gives off CO2 and H2O peaks at 180°C. The reaction takes place at 260—300°C when sodium nitrate oxidizes α-FeC2O4 to Fe (III) compound and releases large amount of CO2 and a little NO and O2. Different mole proportions and particle sizes of reactants have no obvious effect on solid state reaction. Because of the catalyzing effect of Fe (III) compound, sodium nitrate and its reduction product, sodium nitrite decomposes at 380—500°C and Fe (III) compound is transformed into γ-Fe2O3 at 460°C.