论文部分内容阅读
铁基超细粒子催化剂具有优良的F-T反应性能。本工作利用原位Mssbauer谱辅以XRD技术研究了含有钾助剂的F-T合成铁基超细粒子催化剂的结构与还原行为,考察了催化剂组成和第二金属组分(Mn,Zn,Mg)的影响。“纯”铁超细粒子催化剂在氢气中很容易经Fe_3O_4还原为零价铁。第二金属组分的引入,一方面阻碍了催化剂的还原,另一方面稳定了Fe~(2+)的存在而使其成为还原的主要中间相,这有利于反应条件下形成类尖晶石结构的活性相。对于Fe-Mn催化剂,上述效应随锰含量的增加而更趋显著。铁基超细粒子催化剂在氢气中的还原能力依“纯”Fe>Fe-Zn>Fe-Mn>Fe-Mg的顺序递减,这在一定程度上反映了铁与第二金属组分之间相互作用的强弱。
The iron-based ultrafine particle catalyst has excellent F-T reactivity. In this work, the structure and reduction behavior of FT-synthesized iron-based ultrafine particle catalysts containing potassium promoter were studied by in-situ Mssbauer spectroscopy coupled with XRD. The effects of catalyst composition and the content of the second metal component (Mn, Zn, Mg) influences. The “pure” iron ultrafine particle catalyst is easily reduced to zero valent iron by Fe 3 O 4 in hydrogen. The introduction of the second metal component, on the one hand, hindered the reduction of the catalyst, on the other hand, stabilized the presence of Fe ~ (2+) and made it the main mesophase for reduction, which facilitated the formation of spinel- Structure of the active phase. For the Fe-Mn catalyst, the above effect is more pronounced with increasing Mn content. The reducibility of iron-based ultrafine particle catalysts in hydrogen decreases in the order of “pure” Fe> Fe-Zn> Fe-Mn> Fe-Mg, which reflects to some extent the interaction between iron and the second metal component The strength of the role.