石墨烯负载的Fe_(3)O_(4)模型催化剂的制备以及费-托合成性能研究  

Preparation of graphene-supported Fe_(3)O_(4) model catalysts for Fischer-Tropsch synthesis

作　　者：艾心燕 吕帅[1] 刘成超[1] 张煜华[1] 王立[1] 李金林[1] AI Xin-yan;LYU Shuai;LIU Cheng-chao;ZHANG Yu-hua;WANG Li;LI Jin-lin(Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education&Hubei Key Laboratory of Catalysis and Materials Science,South-Central Minzu University,Wuhan 430074,China)

机构地区：[1]中南民族大学,催化转化与能源材料化学教育部重点实验室和催化材料科学湖北省重点实验室,湖北武汉430074

出　　处：《分子科学学报》2023年第1期42-48,共7页Journal of Molecular Science

基　　金：国家自然科学基金资助项目(22072184,22102220,21902187)。

摘　　要：选用多层石墨烯为载体,调变铁盐的浸渍量,通过高温焙烧得到了一系列石墨烯负载的Fe_(3)O_(4)模型催化剂.其中Fe_(3)O_(4)颗粒呈现不规则的多面体,且大于200 nm,较大的尺寸大大抑制了其在反应过程中向碳化铁物种的转化.性能测试结果表明,尽管Fe_(3)O_(4)催化活性不如碳化铁物种,但是Fe_(3)O_(4)本身具有费-托合成活性,且在270℃具有较低的甲烷选择性和较高的C5+选择性.Fischer-Tropsch synthesis is an important way to replace crude oil resources to sustainable energy in the future, and an important process for catalytic conversion of syngas into clean fuel and high value-added chemicals. Iron-based catalysts have been widely used in industrial production due to their advantages of low cost, flexible operation and water-gas conversion activity. However, the phase change of iron-based catalysts during the reaction process is very complex. As many as seven iron species including elemental iron and different types of iron oxide iron carbide are considered to have Fischer-Tropsch synthesis activity. It is very important to understand the evolution of iron species and their roles in the reaction for clarifying the structure-activity relationship of catalysts and designing efficient industrial catalysts. Hematite Fe_(3)O_(4)is often used as the precursor oxide of iron based catalyst, which is converted into iron carbide during the reaction process. It is often considered as an inactivated phase and has high water-gas conversion activity, leading to high CO2selectivity. Wang et al prepared Fe_(3)O_(4)catalyst by using metal organic framework(MOF) as precursor, which would be converted into Fe_(3)O_(4)@Fe5C2during the reaction process. Therefore, the author believed that Fe5C2phase was the key to the catalyst activity. Herein, We used graphene as the support and used the classic preparation method of supported catalyst-impregnation method to prepare iron-based catalyst with different loading capacity. The Fe_(3)O_(4)particles were grown by calcinating at high temperature to prevent excessive carbonization in the reaction process, and the properties of Fe_(3)O_(4)phase were investigated. The results of reaction performance test show that Fe_(3)O_(4)species itself has a certain activity of CO hydrogenation, and the carbonization process of large Fe_(3)O_(4)particles(>200 nm) in the reaction process will be inhibited to a certain extent. With the increase of reaction time, part of Fe_(3)O_(

关 键 词：费-托合成 Fe_(3)O_(4) 碳化铁 物相转变 甲烷选择性 

分 类 号：O611[理学—无机化学]