Fe2O3 nanoparticles encapsulated in TiO2 nanotubes for Fischer–Tropsch synthesis: The confinement effect of nanotubes on the catalytic performance

• A novel Fe-based confinement catalyst was prepared by vacuum-assisted impregnation.
• Catalyst with confinement effect shows an improved yield of oil phase product.
• Fe-in-TNT catalyst has a higher C5+ and C12+ hydrocarbons selectivity than Fe-out-TNT.
• Confinement effect of encapsulated Fe2O3 can enhance the reabsorption of α-olefin in FTS.

The catalysts with high activity and selectivity, especially the latter, play a key role in Fischer–Tropsch synthesis technology. Herein, a novel Fe-based confinement catalyst, Fe2O3 encapsulated in TiO2 nanotubes, was prepared by a method of vacuum-assisted impregnation. The catalyst presented an excellent yield of oil phase hydrocarbons and C5+ selectivity due to the confinement effect. This interesting phenomenon was discussed from the view of the restrained molecular movement and enhanced readsorption of short-chain α-olefins in the confined space of TiO2 nanotube channels. The results over this novel confinement catalyst revealed a promising research prospect on adjusting the product distribution to long-chain hydrocarbons for Fe-based Fischer–Tropsch catalyst.