Magnetite-Catalyzed Enhancement of Heavy Oil Oxidation: Thermal and Kinetic Analysis of Fe(acac)3 Effects on High-Temperature Oxidation Reactions

This study investigates iron acetylacetonate (Fe(acac)3) as a catalyst for enhancing high-temperature oxidation (HTO) during in situ combustion (ISC) of heavy oil. Thermal analysis revealed that Fe(acac)3 decomposes at 360 °C to form crystalline magnetite (Fe3O4). This transformation precedes the HTO regime. Differential scanning calorimetry demonstrated significantly intensified HTO reactions in catalytic systems, as peak temperatures were lower than those in non-catalytic reactions. Kinetic analysis showed that the catalyst reduces HTO activation energy by 15.6%, substantially increasing reaction rates across the HTO temperature range. X-ray powder diffraction confirmed that the mixed-valence Fe2+/Fe3+ configuration in the magnetite structure facilitates electron transfer during oxidation, enabling more complete combustion at lower temperatures. These findings represent a novel approach to catalyst design, from general activity to temperature-specific activation for a more stable and efficient in situ combustion process.