Effect of cobalt loading on reducibility, dispersion and crystallite size of Co/Al_2O_3 Fischer-Tropsch catalyst  

作　　者：熊海峰 张煜华 李金林 古映莹 

机构地区：[1]School of Chemistry and Life Science, South Central University for Nationalities, Wuhan 430074, China [2]School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China

出　　处：《Journal of Central South University of Technology》2004年第4期414-418,共5页中南工业大学学报（英文版）

基　　金：Project(2 0 3730 90 )supportedbytheNationalNaturalScienceFoundationofChina ;project(2 0 0 3ABB0 1 3)supportedbytheTalentedYoungScientistFoundationofHubeiProvince ;projectsupportedbytheExcellentYoungTeachersProgramofMinistryofEducationofChina;projects

摘　　要：Co/Al2O3 Fischer-Tropsch synthesis catalysts with different cobalt loadings were prepared using incipient wetness impregnation method. The effects of cobalt loading on the properties of catalysts were studied by means of X-ray diffraction （XRD）, temperature programmed reduction （TPR）, hydrogen temperature programmed desorption （H2-TPD） and O2 titration. Co-support compound formation can be detected in catalyst system by XRD. For the Co/Al2O3 catalysts with low cobalt loading, CoAl2O4 phase appears visibly. Two different reduction regions can be presented for Co/Al2O3 catalysts, which belong to Co3O4 crystallites （reduction at 320 ℃） and cobalt oxide-alumina interaction species （reduction at above 400 ℃）. Increasing Co loading results in the increase of Co3O4 crystallite size. The reduced Co/Al2O3 catalysts have two adsorption sites, and cobalt loading greatly influences the adsorption behavior. With the increase of cobalt loading, the amount of low temperature adsorption is increased, the amount of high temperature adsorption is decreased, and the percentage reduction and cobalt crystallite size are increased.Co/Al_2O_3 Fischer-Tropsch synthesis catalysts with different cobalt loadings were prepared using incipient wetness impregnation method. The effects of cobalt loading on the properties of catalysts were studied by means of X-ray diffraction (XRD), temperature programmed reduction (TPR), hydrogen temperature programmed desorption (H_2-TPD) and O_2 titration. Co-support compound formation can be detected in catalyst system by XRD. For the Co/Al_2O_3 catalysts with low cobalt loading, CoAl_2O_4 phase appears visibly. Two different reduction regions can be presented for Co/Al_2O_3 catalysts, which belong to Co_3O_4 crystallites (reduction at 320 ℃) and cobalt oxide-alumina interaction species (reduction at above 400 ℃). Increasing Co loading results in the increase of Co_3O_4 crystallite size. The reduced Co/Al_2O_3 catalysts have two adsorption sites, and cobalt loading greatly influences the adsorption behavior. With the increase of cobalt loading, the amount of low temperature adsorption is increased, the amount of high temperature adsorption is decreased, and the percentage reduction and cobalt crystallite size are increased.

关 键 词：Fischer-Tropsch synthesis cobalt/alumina catalyst temperature programmed reduction hydrogen temperature programmed desorption 

分 类 号：O643.3[理学—物理化学]