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采用元素分析、X射线衍射和穆斯堡尔谱等手段研究了喷雾干燥沉淀Fe Cu K/SiO2 催化剂在F T合成反应过程中的物相变化 .结果表明 ,新鲜催化剂样品主要由α Fe2 O3 组成 ,且 81 1%的α Fe2 O3 粒径小于 13 5nm .随着反应时间的延长 ,催化剂表面碳沉积物的含量逐渐增多 ,不饱和度逐渐增大 ;χ Fe5C2 的含量逐渐增多 ,Fe3 O4的含量逐渐减少并趋于稳定 .超顺磁Fe3 + 的含量呈先增加后减少的变化趋势 .由于碳沉积物是由CO生成的 ,而 χ Fe5C2 是由α Fe2 O3 经Fe3 O4生成的 ,故催化剂表面碳沉积物的生成先于 χ Fe5C2 的生成 .
The phase transformation of Fe-Cu K / SiO2 spray-dried precipitates during FT synthesis was studied by means of elemental analysis, X-ray diffraction and Mossbauer spectroscopy.The results show that the fresh catalyst samples mainly consist of α Fe 2 O 3, And the particle size of 81 1% α Fe 2 O 3 is less than 135 nm. With the extension of the reaction time, the content of carbon deposits on the catalyst surface gradually increases and the degree of unsaturation increases. The content of x Fe 5 C 2 gradually increases and the content of Fe 3 O 4 gradually increases Decreases and tends to be stable.The content of superparamagnetic Fe3 + firstly increases and then decreases.Due to the formation of carbon deposit by CO and the formation of χFe5C2 from Fe3O4 by αFe2O3, the surface carbon Sediment formation precedes χ Fe5C2 generation.