Fe_(1-x)O基熔铁催化剂物相及结构变化对其催化合成气制低碳烯烃性能的影响  

Effects of phase and structure of Fe_(1-x)O-based fused iron catalyst on its performance for producing light olefins from syngas

作　　者：杨霞珍[1] 张红 霍超[1] 刘化章[1] Yang Xiazhen, Zhang Hong, Huo Chao , Liu Huazhang(Zhejiang Province Key Laboratory of Heterogeneous Catalysis, Institute of Catalysis Zhejiang University of Technology, Hangzhou Zhejiang 310014, China)

机构地区：[1]浙江工业大学工业催化研究所浙江省多相催化重点实验室,浙江杭州310014

出　　处：《石油化工》2018年第8期775-780,共6页Petrochemical Technology

基　　金：浙江省教育厅一般项目(Y201326527);浙江省自然科学基金一般项目(LY18B060015)

摘　　要：采用高温熔融法制备Fe_(1-x)O基熔铁催化剂,研究了不同反应时间Fe_(1-x)O基熔铁催化剂物相及结构变化与其催化合成气制低碳烯烃性能间的相互关系,考察了Fe_(1-x)O基熔铁催化剂在纯氢气氛中300℃还原6 h后,在1 MPa、340℃、V(H_2)∶V(CO)=1.5、气态空速为11 400 h^(-1)条件下进行合成气制低碳烯烃反应性能。采用XRD,TPD,Raman,TEM等方法对催化剂进行表征。实验结果表明,随着反应进程,CO转化率缓慢增加,低碳烯烃选择性逐渐减小,这是由反应过程中活性相粒径、物相变化和晶面发育协同作用所致。表征结果显示,Fe_3C物相和(006)晶面发育不好的Fe_7C_3物相共存且碳化铁颗粒为20 nm左右时,低碳烯烃选择性最高为60%;催化剂表面纳米碳纤维的存在可以调和表面活性相颗粒大小、碳化程度和晶面发育情况。Fe（1-x）O-based fused iron catalyst were prepared by high temperature melting method.The effects of the phase and structure of the Fe（1-x）O-based fused iron catalyst on its performance were studied.After reduced in pure hydrogen at 300℃for 6 h under 1 MPa,its performance for producing light olefins from syngas was investigated under conditions of V（H2）∶V（CO）1.5,340℃,1 MPa and GHSV11 400 h^（-1）.The catalysts were characterized by XRD,TPD,Raman,and TEM techniques.The results showed that the CO conversion increased slowly and the selectivity to light olefins decreased gradually with the time on stream,which were due to the effects of particle size,phase change and crystal surface development during the reaction.The highest selectivity of light olefins was 60%when the phases of Fe3C and Fe7C3 with（006）poor crystal planes were coexisted,and the surface nanoparticle size was about 20nm.The presence of nanocarbon fibers on the surface of the catalyst could play a role in coordinating the particle size,carbonization degree and crystal planes to improve the selectivity to light olefins.

关 键 词：熔铁催化剂 Fe3C Fe7C3 低碳烯烃 纳米碳纤维 

分 类 号：TQ426.83[化学工程]