改性SiO2对铁基催化剂H2、CO吸附及加氢性能的影响  

Effects of modified SiO2 on H2 and CO adsorption and hydrogenation of iron-based catalysts

作　　者：梁坤 张成华 相宏伟[1,3] 杨勇 李永旺[1,3] LIANG Kun;ZHANG Cheng-hua;XIANG Hong-wei;YANG Yong;LI Yong-wang(State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;University of Chinese Academy of Sciences,Beijing 100049,China;SynfuelsChina Co. Ltd,Beijing 101407,China)

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [2]中国科学院大学,北京100049 [3]中科合成油技术有限公司,国家能源煤基液体燃料研发中心,北京101407

出　　处：《燃料化学学报》2019年第7期769-779,I0001,共12页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金重大研究计划(91545109)项目资助~~

摘　　要：采用溶胶凝胶方法通过掺杂修饰剂M(M=Mn、Zn、Zr、Sr)制备出改性SiO2载体,再用浸渍法将Fe元素负载于该载体上制成系列催化剂。采用X射线衍射(XRD)、氮气物理吸附-脱附、X射线光电子能谱(XPS)等手段表征了催化剂的织构性质、晶相组成和电子性质。利用程序升温手段研究了催化剂的H2还原吸附性质和CO加氢性能。借助动力学分析方法研究了催化剂与H之间的相互作用。结果表明,少量掺杂的修饰剂对催化剂的Fe物相组成以及表面Fe物种电子状态基本没有影响,但降低了催化剂的比表面积以及活性相分散度,削弱了对H2的吸附能力,降低催化剂的H2脱附活化能。Zn、Zr的掺杂抑制了催化剂的还原,而Mn、Sr的掺杂却促进催化剂的还原。Mn、Zn、Zr的掺杂抑制催化剂表面CO的解离吸附,Sr则促进CO的解离吸附,Mn、Zn、Zr、Sr均促进低温区间C-C耦合和加氢反应,其中,Mn、Zr促进加氢的作用更显著。Metal-modified SiO2 supports were prepared by sol-gel method with Mn, Zn, Zr, and Sr cations doping, and then iron-based catalysts supported on modified SiO2 were prepared by the impregnation method. The iron-based catalysts were characterized by XRD, N2 adsorption, and XPS. The reduction adsorption property of H2 and hydrogenation property of CO were studied by temperature programmed methods. The interaction between catalyst and H was studied by kinetic analysis. The results indicate that metal modification has no influence on phase composition of Fe and surface electronic state of Fe species. However, the modification reduces surface area of catalyst and dispersion of active phase, weakens adsorption ability of H2 and lowers H2 desorption activation energy of the catalyst. Zn and Zr doping restrain reduction of catalysts, while Mn and Sr doping promotes reduction of catalysts. The doping of Mn, Zn and Zr inhibits adsorption of CO on the catalyst surface, while Sr promotes dissociation and adsorption of CO. Mn, Zn, Zr and Sr promote C-C coupling and hydrogenation reaction. Among them, Mn and Zr are more prominent.

关 键 词：改性二氧化硅 修饰剂 铁基催化剂 氢气吸附 动力学分析 

分 类 号：TQ529.2[化学工程—煤化学工程]