Effect of pre-treatment conditions on Fe-based catalyst for e-fuel production via modified Fischer-Tropsch synthesis

This work examines the influence of pre-treatment conditions on the Na/Fe3O4 catalyst for CO2-modified FischerTropsch synthesis (FTS) to optimize the conversion of CO2 to liquid hydrocarbons. Using a synergy of Mossbauer spectroscopy, detailed hydrocarbon analysis (DHA) and chemometric analysis, the study identifies critical iron carbide phases formed under different pre-treatments and evaluates their influence on catalytic performance. Specific pre-treatments, notably carburization at 400 °C, were found to promote ε'- Fe2.2C formation, which enhanced C5+ hydrocarbon selectivity, achieving yields between 14 % and 18 % and a balanced light-to-heavy oil ratio. In addition, the synergy of Mossbauer and DHA provided clear insights into phase composition and molecular distributions, enabling a more rigorous analysis of reaction pathways. These results underline the importance of tailored pre-treatment strategies for efficient CO2 utilization, emphasizing the role of combined spectroscopic and chemometric approaches in advancing sustainable fuel synthesis. Overall, this work contrib­utes to the understanding of catalyst behavior in CO2 hydrogenation, highlighting the need for comprehensive liquid phase characterization to optimize catalytic processes for sustainable hydrocarbon production.