浆态床F-T合成Fe/Cu/K/SiO2催化剂中K助剂作用的研究

采用低温N2吸附、H2 TPR、CO2 TPD、MES、XRD，考察了K的加入顺序对两组微球状费托(F-T)合成Fe/Cu/K/SiO2催化剂的织构性质、还原行为、碳化行为、物相变化以及反应性能的影响。结果表明，K的加入顺序对催化剂的织构性质影响很小。先加Si后加K的催化剂具有较强的表面碱性，抑制催化剂在H2气氛下的初始还原，但促进了催化剂的碳化，且在浆态床F T反应中表现出良好的反应稳定性，较高的FTS反应活性，较低的甲烷选择性以及较高的重质烃和烯烃选择性，表现出良好的工业应用前景。

Effect of K on slurry Fischer-Tropsch synthesis over Fe-Cu-K-SiO2 catalysts

The effects of adding order of K on the textural properties, reduction behavior, phase transformation, surface basicity and slurry Fischer Tropsch synthesis (FTS) performances over the spherical Fe-Cu-K-SiO2 catalysts were studied by using N2 physical adsorption, H2 temperature programmed reduction (TPR), CO2 temperature programmed desorption (TPD), Mssbauer spectroscopy and X ray diffraction (XRD). The results indicated that adding order of K could affect the textural properties very slight. The catalysts with later addition of K have stronger surface basicity, which could inhibit the H2 reduction of Fe2O3→Fe3O4 but promote carburization of the catalyst. The catalysts with later addition of K show better reaction stability, higher FTS activity, lower CH4 selectivity and higher selectivity of olefin and heavy hydrocarbon. The results indicate that the later addition of K should be a better choice for Fe-Cu-K-SiO2 catalyst preparation.