Effect of annealing atmosphere on Fischer-Tropsch synthesis performance of Fe/Fe foam structured catalyst

Abstract A facile substrate-assisted hydrothermal method has been developed to synthesize structured Fe/Fe foam catalysts. The hydrothermal products were annealed at various atmosphere to modify the nature of final iron oxide phase. The calcination atmosphere was adjusted by changing the oxygen concentration in the furnace. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), N2 adsorption–desorption, H2-temperature programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the phase composition, morphology, particle size, texture features, reduction and carbonization behavior, as well as surface species and electronic state of the as-synthesized Fe/Fe foam catalysts. With the decrease of oxygen concentration in the annealing atmosphere, FTS activity first increases and then decreases. The catalyst calcined at the opened muffle reveals the highest FTY of 12.7*10−5 molCO/gFe∙s and the lowest methane selectivity (12.2%) compared with other five catalysts.