Preparation of hierarchical porous-structured Fe3O4 microspheres for Fischer-Tropsch synthesis

Hierarchical porous-structured Fe3O4 microspheres for use in Fischer-Tropsch (FT) synthesis were fabricated via a solvothermal reaction mediated by ethylene glycol. Each microsphere was observed to consist of primary nanoparticles that served as active oxides for the FT synthesis reaction. Without additional porous support, the pore structure was well constructed through the self-assembly of the Fe3O4 nanoparticles. Compared to the previously reported Fe catalyst, the current synthesized porous structure appeared to have improved the interparticle connectivity and promote the dispersion of active metal, and hence enhance the selectivity for C5+ hydrocarbons. In particular, 1PFe with an average pore size of 3.71 nm and Fe dispersion of 13.9% exhibited the best selectivity for C5+ (59.0 wt%) combined with the lowest CH4 product fraction (11.3 wt%), as well as a high CO conversion of 93.2%.