A Hydrophilic Supported Fe3O4 Catalyst with Enhanced Light Olefins Selectivity in the Fischer-Tropsch Synthesis

A series of Fe3O4 catalysts supported on chitosan (CTS) were prepared through successive hydrothermal synthesis, cross-linking, and mechanical mixing of CTS. The prepared catalysts were characterized by SEM, XRD, N-2 adsorption-desorption, XPS, FT-IR, TG, H-2-TPR, CO-TPD, C3H6-TPD, and contact angle (CA) analysis, then evaluated for their performance in the Fischer-Tropsch synthesis (FTS). CTS supported Fe3O4 catalyst increased the hydrophilicity of the pristine un-supported Fe3O4. Results revealed that the catalysts exhibit high activity with tuned product distribution in FTS. The water gas shift reaction is facilitated over the Fe3O4/CTS catalysts, and their selectivity for light olefins is significantly improved by inhibiting the secondary reaction of the initial olefins, which was confirmed by C3H6-TPD experiments. The Fe3O4 particle size has a significant influence on product distribution, with larger Fe3O4 particles being beneficial to the formation of light olefins. The 30 % Fe3O4/CTS catalyst has light olefin selectivity of 35 % with an O/P value of 2.19, which are higher than those of 21 % and 0.62 over the pristine Fe3O4.