Enhanced CO₂ Hydrogenation to Hydrocarbons via SIL-Modified Fe-Ru/Al₂O₃ Catalysts: Tailoring Activity and Selectivity Through Support Engineering

The production of hydrocarbons from CO₂ and H₂ is a promising strategy to mitigate CO₂ emissions. While noble metals have traditionally been used as catalysts, their high cost and limited availability have led to the exploration of non-noble metals, such as Ni and Fe, which show potential due to their cost-effectiveness. However, their stability is limited by coke deposition and metal sintering. The addition of small amounts of noble metals as promoters has proven effective in mitigating deactivation and enhancing selectivity toward higher hydrocarbons (C₂⁺).1 Catalytic performance is also highly sensitive to particle size and metal-metal interactions. The incorporation of ionic liquids (ILs) onto the catalyst support surface, forming Supported Ionic Liquids (SILs), enables precise control over particle size. This results in the formation of smaller nanoparticles and promotes enhanced interactions between the metallic phases, thereby improving catalytic activity and stability. Fe-Ru/Al₂O₃ bimetallic catalysts were synthesized and Al₂O₃ was modified by incorporating an imidazolium-derived SIL using a solvent-free methodology. The effects of this modification on the physicochemical properties of the catalysts were evaluated, as well as their impact on performance in the CO₂ hydrogenation reaction.