Recently, metal organic complexes have attracted a lot of attention as oil-dispersed catalysts for in-situ combustion and upgrading of heavy oil. As a relatively new topic, their catalytic mechanism has not been clearly understood. The pyrolysis and oxidation process of metal organic complexes is very important for their catalytic function. In this work, we investigated the pyrolysis and oxidation process of ferric(III) stearate by thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Mössbauer spectroscopy analysis. The results indicated that the pyrolysis and oxidation of ferric(III) stearate is a multistage process. Isothermal treatments experiments show that ferric(III) stearate begins to decompose at about 200 °C and produce ferrous(II) stearate. From 200 to 300 °C, there are three processes that may occur simultaneously: ferric(III) stearate → ferrous(II) stearate; ferrous(II) stearate → Fe₃O₄; and ferric(III) stearate → Fe₃O₄. At 300–350 °C, iron(II) oxide (FeO) is formed with a complete decomposition of ferric(III) stearate. A further heating up to 500 °C leads to the oxidation of FeO to Fe₃O₄, and Fe₃O₄ is the final solid-state product. The degradation kinetics of ferric(III) stearate were analyzed by both isoconversional model and reaction-order model. For reaction-order model, five contributions with the activation energy values in the range of 110–250 kJ/mol were identified and compared with isothermal experiments results. The findings in this work are of great value for understanding the catalytic mechanism of ferric(III) stearate as oil-dispersed catalysts for in-situ catalytic upgrading of heavy oil as well as in-situ combustion for heavy oil recovery.

近年来，金属有机配合物作为用于重油原位燃烧和改质的油分散催化剂引起了广泛关注。作为一个相对较新的课题，它们的催化机制还没有被清楚地理解。金属有机配合物的热解和氧化过程对其催化功能非常重要。在这项工作中，我们通过热重分析 (TGA)、X 射线衍射 (XRD) 和穆斯堡尔光谱分析研究了硬脂酸铁 (III) 的热解和氧化过程。结果表明，硬脂酸三价铁的热解和氧化是一个多阶段的过程。等温处理实验表明，硬脂酸铁 (III) 在 200 °C 左右开始分解并生成硬脂酸亚铁 (II)。从 200 到 300°C，有三个过程可能同时发生：硬脂酸铁 (III) → 硬脂酸亚铁 (II)；硬脂酸亚铁 (II) → Fe₃ O ₄ ; 和硬脂酸三价铁 → Fe ₃ O ₄。在 300–350 °C 时，形成氧化铁 (II) (FeO)，同时硬脂酸铁 (III) 完全分解。进一步加热至 500 °C 会导致 FeO 氧化为 Fe ₃ O ₄和 Fe ₃ O ₄是最终的固态产品。通过等转化模型和反应级数模型分析了硬脂酸三价铁的降解动力学。对于反应级模型，确定了活化能值在 110-250 kJ/mol 范围内的五个贡献，并与等温实验结果进行了比较。这项工作的发现对于理解硬脂酸铁作为油分散催化剂用于重油原位催化升级以及原位燃烧用于重油采收的催化机理具有重要价值。