低碳化学与化工2025，Vol.50Issue(5)：93-100,119,9.DOI:10.12434/j.issn.2097-2547.20240400
PFTS改性Fe3O4@SiO2催化剂对费托合成产物分布的影响
Effect of PFTS modified Fe3O4@SiO2 catalysts on product distribution in Fischer-Tropsch synthesis
摘要
Abstract
One of important ways to achieve clean and efficient utilization of coal is through Fischer-Tropsch synthesis(FTS)to prepare high value-added chemicals via CO hydrogenation.However,while generating hydrocarbons,a large amount of H2O is also produced as by-product.H2O will oxidize the active center,leading to a decrease in reaction rate,and promote the water gas shift(WGS)reaction,generating a large amount of CO2 and reducing the efficiency of carbon utilization.At the same time,the primary olefins in the FTS products are easy to be re-adsorbed for secondary hydrogenation reactions,decreasing the selectivity of olefins.Based on the characteristics of the FTS product distribution,the control of products can be achieved by adjusting the surface hydrophilicity of Fe-based catalysts.Fe3O4@SiO2 catalysts with different shell thicknesses were produced by solvothermal method and Stöber methods,and Fe3O4@SiO2-3-PFTS catalyst with hydrophobic and oleophobic(hereinafter referred to as"amphiphobic")properties were prepared by perfluorodecyltriethoxysilane(PFTS)as a modifier.The effects of the shell thickness and amphiphobic modification on the catalyst activity and FTS product distribution were investigated.The catalysts were characterized by SEM,TEM,FT-IR,XRD,H2-TPR and so on,and their catalytic performances were tested under the conditions of 300 ℃,1.5 MPa,gas space velocity of 3000 h-1 and V(H2)∶V(CO)=2∶1.The results show that the prepared catalysts have complete core-shell structures and uniform shell thickness.Fe3O4@SiO2-3-PFTS catalyst exhibits good amphiphobic properties.With the increase of the thickness of SiO2 shell layer,the secondary hydrogenation reaction of primary olefins is enhanced,and the generation of heavy hydrocarbons is significantly inhibited.The selectivity of alkanes with two to four carbon atoms(C20～C40)increases from 21.5％(Fe3O4)to 46.8％(Fe3O4@SiO2-3),and the selectivity of hydrocarbons with five or more carbon atoms(C5+)decreases from 47.7％(Fe3O4)to 21.5％(Fe3O4@SiO2-3).Fe3O4@SiO2-3-PFTS catalyst inhibits the WGS reaction and secondary hydrogenation of primary olefins.After reaction for 12 h,the selectivity of CO2 is 14.2％,and the selectivity of olefins with two to four carbon atoms(C2=～C4=)is 19.7％,and selectivity ratio of olefins and alkanes in C2～C4 products is 0.68.The product distribution is regulated.关键词
费托合成/Fe3O4@SiO2催化剂/双疏改性/产物分布Key words
Fischer-Tropsch synthesis/Fe3O4@SiO2 catalyst/amphiphobic modification/product distribution分类
化学化工引用本文复制引用
张雪建,王舜,张帅,王康洲,高新华,赵天生,张建利..PFTS改性Fe3O4@SiO2催化剂对费托合成产物分布的影响[J].低碳化学与化工,2025,50(5):93-100,119,9.基金项目
国家自然科学基金(22368041) （22368041）
中央引导地方科技发展专项(2023FRD05030). （2023FRD05030）
