Effect of Na, Cu and Ru on metal-organic framework-derived porous carbon supported iron catalyst for Fischer-Tropsch synthesis

Fischer-Tropsch synthesis (FTS) is studied over Metal-organic framework (MOF) based porous carbon supported iron catalysts promoted with Na, Cu and Ru metals. The FTS results showed that all promoters can enhance CO conversion, FT product yield (FTY), and CO2 selectivity is also increased. Among all promoters, Cu-based sample exhibits the best promoting effect in activity (FTY=0.154 molCO g Fe−1 h −1). Interestingly, the activity is about 2 times higher to that of unpromoted catalysts. Ru-contained sample exhibits the most significant influence on the light hydrocarbon production, with the C1–4 hydrocarbon selectivity above 70%. Na-contained sample performed the highest C5+ selectivity of 66% with a medium CO conversion of 51%. The improved FTS activity and selectivity of promoted catalysts is related to the decrease in iron particle size as confirmed by X-ray diffraction (XRD), and transmission electron microscopy (TEM). It is confirmed, the small iron particles of the promoted catalyst are stabilized on the surface of carbon matrix, preventing further aggregation at high temperature, which is contributed to the improved FTS performance. Our research study showed that Na, Cu and Ru can not only affect the distribution of resulting products but also improve the activity of FTS. In short, the effect of Cu is remarkable on the MOF-derived catalyst. Similarly, the MOF-derived porous carbon catalysts confined the iron species during the reaction process, provide a clear structure-activity relationship between the promoters and the catalytic performance. Finally, this novel work can provide a new pathway for metal-organic framework-derived Fe-embedded porous carbon catalysts for Fischer-Tropsch synthesis.