Fischer-Tropsch Conversion of H2 Lean Syngas Over Mesoporous Silica-Carbon Composite Supported and Cu Promoted Fe Catalysts

Iron based Fischer-Tropsch (FT) catalysts have widely been used for liquid hydrocarbon synthesis by using syn gas (CO + H-2) as a reactant. The water gas shift activity of iron makes it a potential catalyst for liquid hydrocarbon synthesis by using H-2 deficient syngas a reactant. Despite numerous studies on supported iron-based catalysts, there is still room for improvement in our understanding of the specifics of supported iron-based catalysts for FT reactions. The aim of the present study was to explore the role of mesoporous silica-carbon composite (SCn) materials as a support for development of iron based FT catalyst. SCn material was synthesized with different carbon/silica (C/Si) mole ratio. The high surface area, ordered mesoporosity and narrow pore size distributions of SCn material made it a potential support material for development of iron based FT catalyst which facilitated the diffusion of reactant gas molecule inside the mesoporous channel of catalyst. The cylindrical mesoporous channel itself acted as a nanoreactor which facilitate conversion of syn gas to liquid hydrocarbon. The copper promotion also played synergistic role by decreasing the reduction temperature of iron species as well as water gas shift (WGS) activity. The carbon containing support material also played promoting role for iron based FT catalyst. Presence of copper and carbon reduced the reduction temperature of iron species as well as growth of active metal species. Besides, carbon also reduced the formation of silica-iron complex which increased the active catalytic site. This study may boost the development of iron based catalyst for pilot scale study of FT reaction.

Automated summary

The aim of this study was to investigate the role of mesoporous silica-carbon composite (SCn) materials as a support for iron based FT catalyst. SCn material with high surface area, ordered mesoporosity and narrow pore size distributions facilitated the diffusion of reactant gas molecules and acted as nanoreactors for the conversion of syngas to liquid hydrocarbon. The addition of copper and carbon promoted the reduction of iron species and the growth of active metal species, while suppressing the formation of silica-iron complexes. This study has significant implications for the development of iron based catalysts for pilot scale investigation of FT reaction.