Rapidly Quenched Skeletal Fe-Based Catalysts for Fischer−Tropsch Synthesis

A novel, rapidly quenched skeletal Fe catalyst (RQ Fe) has been prepared by alkali leaching of the Fe50Al50 alloy solidified by the rapid quenching technique and tested in gas phase Fischer−Tropsch synthesis (FTS). Characterizations demonstrate that the RQ Fe catalyst has larger specific surface area, smaller crystallite size, and higher population of the Fe(111) surface than the conventional Raney Fe catalyst prepared from the naturally solidified Fe50Al50 alloy. As compared to Raney Fe, which has FTS activity equivalent to the precipitated Fe catalyst while higher than the fused Fe catalyst, RQ Fe is 25% more active. Promotion of the RQ Fe catalyst with Mn or K further improves the FTS activity, selectivities to alkenes and higher alkanes, as well as the catalytic stability, showing that the rapid quenching technique is promising in the preparation of skeletal Fe-based catalysts with improved FTS performance.