文献类型：期刊文献

中文题名：活化气氛对CO_2加氢制取低碳烯烃Fe-K催化剂构-效关系

英文题名：Activation atmospheres on structure-performance relationship of K-promoted Fe catalysts for lower olefin synthesis from CO_2 hydrogenation

作者：张玉龙[1];邵光印[1];张征湃[1];刘向林[1];张超[1];徐晶[1];韩一帆[1]

机构：[1]化学工程联合国家重点实验室华东理工大学,上海200237

年份：2018

卷号：69

期号：2

起止页码：690

中文期刊名：化工学报

外文期刊名：CIESC Journal

收录：CSTPCD;;EI(收录号：20184205947635);Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2017_2018】；

基金：国家自然科学基金项目(21576084;91534127)~~

语种：中文

中文关键词：CO2加氢;Fe-K催化剂;活化气氛;低碳烯烃;构-效关系

外文关键词：CO2 hydrogenation; Fe-K; activation atmospheres; lower olefins; structure-performance relationship

摘要：CO_2加氢直接制取低碳烯烃是实现其资源化利用的重要途径。通过热分解法制备了5种不同K含量(1%、3%、5%、7%、9%)的Fe-K催化剂用于CO_2加氢反应,结果表明Fe95-K5(95%Fe-5%K,质量分数)催化剂具有最优的活性及C2~C4烯烃选择性;随后对Fe95-K5催化剂进行了10%H2/Ar、10%CO/Ar及5%CO/5%H2/Ar3种不同气氛活化处理以及CO_2加氢反应。结果发现,10%CO/Ar活化的催化剂具有最高的C2~C4烯烃选择性(38.1%)及链增长能力(α=0.644)。此外,还通过X射线衍射、Raman、程序升温等表征技术揭示了催化剂在不同活化气氛下的结构演变历程。研究发现,10%CO/Ar与5%CO/5%H2/Ar活化的催化剂会生成γ1型碳化铁结构,而10%H2/Ar活化的催化剂则会在反应过程中生成γ2型碳化铁结构,两种碳化铁结构对CO_2解离均有促进作用。
Lower olefins synthesis from direct CO2 hydrogenation over Fe-based catalysts is an important process of CO2 utilization. Iron catalysts with different K loading（1%, 3%, 5%, 7% and 9%） prepared by thermal decomposition were used in CO2 hydrogenation. Fe95-K5（95%Fe-5%K,mass fraction） catalyst showed the highest activity and C2—C4 olefin selectivity. Further enhancement on Fe95-K5 catalytic performance was achieved by pre-treatment under three different activation atmospheres（10%H2/Ar, 10%CO/Ar, 5%CO/5%H2/Ar） prior to CO2 hydrogenation. 10%CO/Ar-activated catalyst showed the highest C2—C4 olefin selectivity（38.1%） and chain growth probability（α=0.644）. In addition, the structure evolution of Fe95-K5 during activation and CO2 hydrogenation was characterized by X-rays diffraction（XRD）, Raman and temperature-programmed hydrogenation（TPH） techniques. CO introduction in pretreat process accelerated formation of iron carbides. γ1-iron carbide was formed after pretreating in 10%CO/Ar and 5%CO/5%H2/Ar, while γ2-iron carbide was produced in the hydrogenation reaction after pretreating in 10%H2/Ar. Both carbides could promote CO2 dissociation on catalyst surface.