高度分散的Fe2O3/SiO2的合成及对F-T反应的催化性能

以初湿浸渍法为基础,柠檬酸为分散剂,制备出Fe2O3在SiO2载体上高度分散的F-T催化剂,通过N2吸脱附技术、X射线衍射、扫描透射电镜和程序升温还原对催化剂的结构,形貌及组成进行表征,结果表明,在柠檬酸分散作用下,浸渍过程中Fe离子与SiO2载体之间的静电吸附作用使Fe离子稳定、均匀地分散于SiO2表面,在烘干、焙烧过程中未发生团聚现象,形成高度分散、均匀的纳米颗粒,粒径平均尺寸为1.1nm。以F-T合成反应作为模型反应对催化活性进行表征,该法合成的催化剂表现出较优异的稳定性,反应500h后CO转化率保持在35.1%。

Preparation and Fischer-Tropsch Catalytic Activity of High Dispersed Fe2O3/SiO2 Catalyst

An efficient method to synthesize highly dispersed Fe2O3/SiO2 catalysts for Fischer-Tropsch reaction is described. The synthesis of well-dispersed Fe2O3/SiO2 is carried out via incipient wetness method (IW) in the presence of citric acid. The resulting samples are characterized by using N2 adsorption-desorption techniques, X-ray Diffraction (XRD), Scanning Transmission Electron Microscopy (STEM), and Temperature Programmed Reduction (TPR). The results show that iron oxide is well-dispersed over the SiO2 support in the presence of citric acid. Owing to the electrostatic adsorption interactions between the iron species and the SiO2 support, sintering and agglomeration are inhibited during the preparation process so that high dispersed Fe2O3 particles are obtained after drying and calcincation. The particles size of the deposited Fe2O3 is uniform and the average size is 1.1 nm. In the F-T reaction, the catalyst shows higher F-T activity and stability. The CO conversion reaches 35.1% after 500 h reaction.