Comparing the deactivation behaviour of Co/CNT and Co/γ-Al_2O_3 nano catalysts in Fischer-Tropsch synthesis

作     者：Ahmad Tavasoli Saba Karimi Somayeh Taghavi Zahra Zolfaghari Hamideh Amirfirouzkouhi Ahmad Tavasoli;Saba Karimi;Somayeh Taghavi;Zahra Zolfaghari;Hamideh Amirfirouzkouhi

作者机构：School of ChemistryCollege of ScienceUniversity of TehranTehranIran 

出 版 物：《Journal of Natural Gas Chemistry》 (天然气化学杂志（英文版）)

年 卷 期：2012年第21卷第5期

页      面：605-613页

核心收录：

学科分类：081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 

主　　题：Fischer-Tropsch synthesis cobalt carbon nanotube γ-alumina deactivation 

摘      要：An extensive study of Fischer-Tropsch （FT） synthesis on cobalt nano particles supported on γ-alumina and carbon nanotubes （CNTs） catalysts is reported.20 wt% of cobalt is loaded on the supports by impregnation *** deactivation of the two catalysts was studied at 220 C,2 MPa and 2.7 L/h feed flow rate using a fixed bed *** calcined fresh and used catalysts were characterized extensively and different sources of catalyst deactivation were *** of cobalt-support mixed oxides in the form of xCoO yAl2O3 and cobalt aluminates formation were the main sources of the Co/γ-Al2O3 catalyst *** sintering and cluster growth of cobalt nano particles are the main sources of the Co/CNTs catalyst *** the case of the Co/γ-Al2O3 catalyst,after 720 h on stream of continuous FT synthesis the average cobalt nano particles diameter increased from 15.9 to 18.4 nm,whereas,under the same reaction conditions the average cobalt nano particles diameter of the Co/CNTs increased from 11.2 to 17.8 ***,the initial FT activity of the Co/CNTs was 26% higher than that of the Co/γ-Al2O3,the FT activity over the Co/CNTs after 720 h on stream decreased by 49% and that over the Co/γ-Al2O3 by 32%.For the Co/γ-Al2O3 catalyst 6.7% of total activity loss and for the Co/CNTs catalyst 11.6% of total activity loss cannot be recovered after regeneration of the catalyst at the same conditions of the first regeneration *** is concluded that using CNTs as cobalt catalyst support is beneficial in carbon utilization as compared to γ-Al2O3 support,but the Co/CNTs catalyst is more susceptible for deactivation.