Comprehensive study of cobalt-based hybrid catalysts for selective liquid fuel production via Fischer–Tropsch synthesis

The synthesis of alternative liquid fuels from renewable resources via power-to-liquids (PtL) or biomass-to-liquids (BTL) processes requires intensification due to the scattered distribution and fluctuating properties of these resources. For process intensification, a hybrid Fischer–Tropsch catalyst that selectively produces naphtha and liquid fuels in a single stage have been proposed. However, the critical variables in shaped hybrid catalysts, including catalytic composition, component proximity, zeolite acid characteristics, and mesoporous structure in zeolite, have not been extensively examined, and their long-term stability remains uninvestigated. In this study, the proximity of catalytic sites along with the physicochemical properties of the zeolite, were found to significantly affect hydrocarbon selectivity. Specifically, the mesoporous structure in zeolite and close distance between cobalt and zeolite acid sites enhanced the selective production of liquid fuels. Among integration strategies, mixed particles containing zeolites having Si/Al ratios of ≤40 effectively promoted the isomerization and cracking functions of the zeolite, increasing selectivity for liquid fuels (C 5 –C 20 ). Notably, the FT-H-ZSM-5-40 (MP)* catalyst, prepared by peptizing H-ZSM-5 and Pt-promoted Co/Al 2 O 3 catalysts with a binder, exhibited enhanced selectivity for C 5 –C 20 hydrocarbons (> 79 %) and high stability over a 900-hour reaction. Based on the experimental results, an Anderson–Schulz–Flory model with deviation was suggested, offering a tailored approach depending on targeted products.