LAUSR

Abstract Metal Organic Frameworks makes it being used as a template to prepare highly dispersed catalysts. The Fe@C catalyst prepared by pyrolysis of Fe-MOF precursor, depicts a core-shell structure with carbon layers being coated on the outer surface of iron species. Since the diffusion of molecules through carbon layers is suppressed, the active iron sites in the interior could not be fully utilized. Based on this realization, tetraethyl orthosilicate (TEOS) as the silicon source was introduced the MOF during the preparation process of Fe-MOF. After carbonization and calcination, the carbon layer was removed while the iron species were confined by the SiO2 yielding the FexOy@SiO2 catalyst. The confinement effect of SiO2 greatly prevented the agglomeration of iron species during calcination process. Compared with Fe@C catalyst without silicon source, the prepared FexOy@SiO2 catalyst resulted in an enhanced FTS activity with FTY as 4.54 × 10−4 molCO/(gFe⋅s) and gasoline fraction selectivity. Upon using same quantity of TEOS, the dispersion degree of iron species and the confinement effect of SiO2 could be regulated by just changing the introduction order of TEOS, corresponding different FTS performances. The FexOy-SiO2 interaction in the catalyst and its influence on the properties of the FexOy@SiO2 catalyst are discussed and structure-activity relationship was explored.