Zr助剂对铁基催化剂F-T合成性能的影响

Effect of Zr promoter on iron-based catalyst for Fischer-Tropsch synthesis

采用N2物理吸附、程序升温还原、X射线衍射和穆斯堡尔谱等分析方法研究了助剂Zr含量对铁基费托合成催化剂结构、还原碳化行为及物相的影响,在n(H2)/n(CO)=0.67,270℃,1.5MPa和1.0L.g-1.h-1条件下,在固定床反应器中考察Zr含量对铁基催化剂费托合成性能的影响。结果表明,添加少量Zr能提高催化剂的比表面积,促进催化剂的还原和碳化,提高催化剂的反应活性,增加Zr浸渍量则降低了催化剂比表面积,抑制催化剂的还原和碳化,降低催化剂的活性同时加速催化剂的失活。当n(Zr):n(Fe)=0.01时,催化剂Zr-1具有高的CO转化率和高的C5+选择性。

The effects of promoter Zr content on the structure,reduction behavior and phase transformation of the iron-based catalysts for Fischer-Tropsch synthesis（FTS） were investigated using N2 adsorption,temperature-programmed reduction,X-ray photoelectron spectroscopy and M ssbauer effect spectroscopy.The FTS performances of the iron-based catalysts were studied in a fixed-bed reactor under the conditions of H2/CO molar ratio of 0.67,270℃,1.5MPa and space velocity of 1.0 L·g-1·h-1.The results showed that small amount of Zr increased the BET surface area,promoted the reduction/carburization and improved the activity of the catalyst.While large amounts of Zr addition decreased the surface area,suppressed the reduction/carburization of the catalyst,decreased the activity and speeded up the catalyst deactivation.The optimal catalyst with Zr/Fe molar ratio of 0.01 had high CO conversion and high selectivity to C5＋ hydrocarbons.