Abstract: A series of Fe-based catalyst samples with different amounts of SO2-4 for Fischer-Tropsch synthesis (FTS) were prepared by iso-volume impregnation of the FeCuK/SiO2 precursor with NH4HSO4 solution. The catalyst samples were characterized by atomic emission spectroscopy, N2 adsorption,X-rayphotoelectron spectroscopy, temperature-programmed reduction, and Mssbauer effect spectroscopy. The catalytic performance of the catalyst samples for the FTS reaction was measured in a continuous stirred tank slurry reactor under the reaction conditions ofn(H2)/n(CO)=0.67, WHSV=2000h-1, 1.5 MPa, and 250 ℃. The results showed that the addition of SO2-4 promoted the reduction of the catalyst in H2. A low level of SO2-4 slightly influenced the extent of carburization, and the excessive addition of SO2-4 restrained carburization apparently in syngas. The catalyst samples with different SO2-4 amounts displayed different FTS reactivity, but all the samples were stable during 500 h on stream. Moreover, the addition of SO2-4 could suppress the water-gas shift reaction. The low level of SO2-4 suppressed methane selectivity and promoted slightly alkene selectivity.

Key words: sulfate, Fischer-Tropsch synthesis, iron-based catalyst, slurry reactor