费-托合成铁催化剂中金属与担体相互作用的考察  

INVESTIGATION OF METAL-SUPPORTINTERACTION(MSI) OF FISCHER-TROPSCH IRON CATALYSTS

作　　者：王承玉[1] 章素[1] 蔡海林[1] 潘立金[1] 梁东白[1] 林励吾[1] 

机构地区：[1]中国科学院大连化学物理研究所

出　　处：《燃料化学学报》1989年第2期183-188,共6页Journal of Fuel Chemistry and Technology

摘　　要：将费-托合成铁催化剂Fe/Al_2O_3和Fe/SiO_2在空气中经一系列温度(25、120、480、650、780和1000℃)予处理并在相同条件(H_2、480℃、4h)下还原,然后作原位穆斯堡尔谱和高分辨电镜的考察,结果表明,在较低温度下予处理时,随着予处理温度的升高,Fe/Al_2O_3和Fe/SiO_2中的铁被还原为Fe(O)的量增加,但当达到某一温度(Fe/Al_2O_3为650℃、Fe/SiO_2为480℃)时出现了转折,即随着予处理温度的增加,Fe(O)%降低,意味着MSI由原来的减弱变为增强。在较低的予处理温度时,生成了难以还原的铝酸铁盐和硅酸铁盐,使MSI效应为主。适当增强MSI对提高低碳烯烃选择性有利。Fischer-Tropsch iron catalysts Fe/Al_2O_3 and Fe/SiO_2 which were pretreated in air at different temperatures (25℃,120℃,480℃,650℃, 780℃ and 1000℃) for 4h following reduction under the same conditions (H_2, 450℃, 4 h) have been studied by in-situ Mossbauer spectroscopy and highresolution electron microscopy. The results show that the percentage of Fe(0) in Fe/Al_2O_3 and Fe/SiO_2 passes through maxima at pretreatment temperatures of 650℃ and 480℃ respectively. It is ascribed to the possibility that when pretreating the samples at temperatures below the turninf points the increase in particle sizes of Fe_2O_3 which favors its reduction to iron metal, predominates over the increase in MSI for both Fe/Al_2O_3 and Fe/SiO_2, while the contrary occurs at higher pretreatment temperatures.The maximum of Fe(0)% formation (or the minimum of MSI) occurs at pretreatment temperatures of 650℃ and 480℃ for Fe/Al_2O_3 and Fe/SiO_2 respectively.MSI which is attributed to the formation of stable Fe (Ⅲ) species (Fe(Ⅲ) aluminate and Fe(Ⅲ)silicate, has been found to influence the selectivity of F-T reactions.

关 键 词：费托合成 铁催化剂 AL2O3 SIO2 

分 类 号：TQ426.8[化学工程]