Effective Fe/K Catalyst for Fischer–Tropsch to Light Alkenes

Carbon-containing materials such as coal and biomass may be processed to syngas, which can be further converted to ethylene, propylene and butylenes directly or indirectly. Potassium-promoted iron catalysts, loaded over high temperature annealed supports ZnAl 6 O 10 and ZnAl 10 O 16 , are developed and compared with other reference catalysts. All catalysts were investigated by XRD, ICP, nitrogen physisorption, FESEM, CO 2 -TPD, and direct Fischer–Tropsch to light alkenes (FTO) reaction tests. Without the assistance of any surface modifier or molecular sieve, at a total pressure of 2 MPa (≈ 20 bar), catalyst Fe/K/ZnAl 6 O 10 reached a C 2 = –C 4 = hydrocarbon selectivity of 70%, which is one of the highest light alkene selectivity values documented for iron-based FTO catalysts. Relationships between characterization data and catalytic performance were discussed. Graphical Abstract Potassium-promoted iron catalysts, loaded over high temperature annealed supports ZnAl 6 O 10 and ZnAl 10 O 16 , are compared with reference catalysts. Without the assistance of any surface modifier or molecular sieve, catalyst 15%Fe/2%K 2 O/83%ZnAl 6 O 10 achieves its maximum CH selectivity of light alkenes (C 2 = –C 4 = ) of 70%.