Direct Conversion of Bio-syngas to Gasoline Fuels over a Fe3O4@C Fischer-Tropsch Synthesis Catalyst

Fischer-Tropsch synthesis (FTS), as an alternative process for producing liquid fuels from bio-syngas, is receiving renewed interest for both industrial and academic applications. A novel carbon-encapsulated Fe3O4 nanocatalyst is designed to optimize the product distribution of hydrocarbons. Several techniques such as XRD, H2-TPR, BET, XPS, LRS, SEM and TEM are used to characterize the catalyst samples. The characterization results indicated that combination of glucose and iron species led to the formation of carbon-encapsulated Fe3O4 nanoparticles (Fe3O4@C), and the increasing glucose content in the catalysts resulted in the decrease of Fe3O4@C nanoparticle sizes. Fe3O4@C with smaller particle sizes provided more surface amounts of iron species, which facilitated the reduction of iron oxides and formation of active iron sites. However, the excess addition of glucose resulted easily in the formation of more carbon deposition on the surface of Fe3O4@C. Compared to the traditional Fe2O3 catalyst, the Fe3O4@C catalyst showed excellent catalytic activity and higher selectivity of gasoline products. Especially, decreasing nanoparticle sizes for the carbon-encapsulated Fe3O4 catalysts improved obviously the catalytic activity and increased the selectivity of C2-4 hydrocarbons.