Insights into the Structure–Performance Relationship and Viscosity Reduction Performance of Recyclable Magnetic Fe/Zeolite for Crude Oil Aquathermolysis

[Image: see text] Elucidating the structure–performance relationship of zeolites and their synergy with metals for the catalytic aquathermolysis of crude oil is crucial for designing efficient catalysts. Herein, the structure–performance relationship between the magnetic Fe-loaded zeolite’s physicochemical properties and aquathermolysis performance is mainly explored. First, the catalytic aquathermolysis performance of various porous materials (Y, β, MCM-41, and ZSM-5 zeolites) was probed to investigate the effect of different topological structures on the viscosity reduction of heavy oil. Results showed that ZSM-5 has a favorable pore structure and acidity, and its viscosity reduction performance is 1.7–4.1 times those of other zeolites; therefore, it is more suitable as a carrier for aquathermolysis to reduce viscosity. Then, Fe substance (such as Fe(2)O(3) and Fe(3)O(4)) was loaded onto the ZSM-5 support. It was found that Fe(3)O(4)/ZSM-5 had better performance compared with pure ZSM-5 and Fe(2)O(3)/ZSM-5, which could reduce the viscosity of heavy oil by 20.3%. Importantly, the Fe(3)O(4)/ZSM-5 catalyst is easily separated from crude oil due to its magnetism, hence it has the potential to be recycled and reused. In addition, the potential structure–performance relationship was systematically studied by X-ray diffraction (XRD), elemental analysis (EL), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). As a result, it was considered that Fe(3)O(4)/ZSM-5 broke C–S bonds and reduced the heavy components (resin and asphaltene) of crude oil. This study has a certain guiding significance for developing heterogeneous magnetic hydrothermal viscosity reduction catalysts.