Enhanced Fischer–Tropsch performances of graphene oxide-supported iron catalysts via argon pretreatment†
Graphene oxide (GO)-supported iron oxide nanoparticles (NPs) have been successfully synthesized by a hydrothermal method and used as Fischer–Tropsch synthesis (FTS) catalysts. GO with oxygen-containing groups may have a strong interaction with iron oxide NPs, retarding the contact between active sites and syngas. Argon pretreatment is used to modify the physical and chemical properties of catalysts with the purpose of enhancing FTS performances. The catalysts are thoroughly characterized by N2 physisorption, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, temperature-programmed reduction, and Mössbauer spectroscopy. The pretreatment of catalysts in argon at 500 °C for 5 h can effectively increase the surface area and defects, weaken the Fe–GO interaction and expose more catalytically active sites. The Fe/GO-500 catalyst shows improved reduction and carburization behaviors, high CO conversion activity and C5+ selectivity, and excellent stability in the FTS reaction.