摘要：本实验通过浮动催化热裂解法制备的碳包覆渗碳体纳米复合颗粒，经透射电子显微镜、X射线衍分析，700 ℃下制备样品为-氧化铁，其粒径为1〜5 nm碳壳平均厚度为〜1.2 nm；900 ℃下制备样品为渗碳体，颗粒的直径为5〜20 nm，碳壳平均厚度为〜2.0 nm；1100℃下制备样品为渗碳体，颗粒的直径为10〜30 nm，碳壳平均厚度为〜2.5 nm。由XRD结果表明Fe3C催化剂经过高温催化合成气后，对反应后催化剂物象通过X射线衍射分析，确认催化剂物象由反应前的Fe3C转化为Fe5C2。该转化过程可能是由于Fe3C在合成气大量一氧化碳存在的气氛中，在高温下被再次渗碳使得碳化物的碳铁比由1:3提高到2:5，从而由Fe3C转化为Fe5C2。该转化也表明催化低碳烯烃的催化剂应该为Fe5C2，在900摄氏度时，峰值不多，但是很平均，催化选择性优良，催化性能较好，在1100摄氏度时，波峰比较尖锐，说明只有一些催化选择性较好，不能适用于所有催化反应，故得出我们在900摄氏度时为最佳的催化剂制备温度。

关键词：催化剂；核壳结构；低碳烯烃

Synthesis of iron carbon alloy particles and their catalytic properties

Abstract: In this experiment, the carbon coated cementite nanocomposite particles were prepared by the floating catalytic pyrolysis method. Through the transmission electron microscope and X ray diffraction analysis, the samples were prepared at 700 degrees centigrade. The average thickness of the particle size from 1 to 5 nm was ~ 1.2 nm; the sample prepared at 900 C was Carburized, the diameter of the particles was 5 to 20 nm, carbon The average thickness of the shell is from 2 nm to 1100 nm, and the diameter of the samples is 10 ~ 30 nm and the average thickness of the carbon shell is 2.5 ~ 2.5. The results of XRD show that Fe3C catalyst has been catalyzed by high temperature catalyzed synthesis of gas, and the catalyst image after reaction is analyzed by X ray diffraction, and it is confirmed that the catalyst image is transformed from Fe3C before reaction to Fe5C2. The transformation process may be due to the presence of Fe3C in the atmosphere of a large amount of carbon monoxide in the syngas and the re carburization of the carbides at high temperatures to increase the carbon and iron ratio of the carbides from 1:3 to 2:5, thus transforming from Fe3C to Fe5C2. The conversion also shows that the catalyst for the catalytic low carbon olefin should be Fe5C2, at 900 degrees centigrade, the peak value is not much, but it is very average, the catalytic selectivity is good, the catalytic performance is good. At 1100 degrees centigrade, the peak is sharper, indicating that only some catalytic selectivity is better and can not be applied to all the catalytic reactions, so I come to the conclusion. They are the best catalyst preparation temperature at 900 ℃.

Key words：Catalysts, Core-Shell structure, Light olefin

目录

1 绪论 - 1 -

1.1 铁碳合金在费托合成中的应用 - 1 -

1.1.1 费托合成 - 1 -

1.1.2 费托合成催化剂及产物分布 - 3 -

1.1.3 费托合成工作原理 - 5 -

1.2 炭化铁纳米极材料 - 8 -

1.3 炭化铁制备进展史 - 9 -

1.4 费托合成反应活性测试结果 - 10 -

1.5实验目的和研究背景 - 11 -

2 实验部分 - 12 -

2.1 实验原料 - 12 -

2.2 实验器材 - 12 -

2.3 实验装置 - 13 -

2.4 铁碳合金颗粒的制备 - 13 -

3 结果讨论 - 15 -

3.1 铁碳合金物像分析 - 15 -

3.2催化性能以及XRD分析 - 20 -

4.结论 - 21 -

1 绪论

   采用了低碳烯烃的不同含烯烃的催化剂进行分开实验，以证明在不同情况下的催化效果不同，和选择性和转化率的不同，其中用到了碳化铁的不同形式。

   低碳烯烃是重要的有机化工原料，迅速的化工业发展已经大大的影响了整个石化工业的发展和市场背景，而由于对此新材料的急需以及应用广泛，这种合成催化的原料已经被投入了极大的关注和支持。