微乳液法制备超细氧化铁的TPR研究

The TPR Research of Ultrafine Fe_2O_3 Prepared by Microemulsion

以十二烷基苯磺酸钠(DBS)为表面活性剂,甲苯为油相,用微乳液法制备了超细氧化铁.样品的粒径分布和程序升温还原(TPR)测试表明,样品为超细Fe2O3并且粒径大小与其还原性能密切相关.TPR还原峰的动力学分析表明:Fe2O3的还原分三步进行:Fe2O3→Fe3O4→FeO→Fe,每步还原反应都是一级反应.通过粒径与TPR的分析,确定了制备超细氧化铁的条件:加料方式为正加法、沉淀温度为289 K、甲苯加入量为35mL、DBS加入量为6 mL.

The ultrafine particles of Fe2O3 were prepared in the microemulsion. In the oil-water -two phase system, Dodecylbenzenesulfonic acid sodium（DBS） and methylbenzene were used as surfacetant（S） and oil phase （O）. The sample was researched by particle diameter distributing and temperature-programmed reduction （TPR）. It was indicated that the particles were uhrafine Fe2O3 and the particle diameter size was tied up with the reduction performance. The analysis of the TPR showed that the reduction process was Fe2O3→Fe3O4→FeO→Fe ; each step was apparent first-order reaction. The optimization of preparation conditions were normal method for precipitation ;289 K as precipitation temperature ;35 mL methylbenzene and 6 mL DBS adding to,respectively.