摘要
采用TPR,TG和DTA技术研究了铬铬系中变催化剂中Fe_2O_3的还原历程及CeO_2对其还原行为的影响。结果表明Fe_2O_3的基本还原历程为Fe_2O_3→Fe_3O_4→Fe,其还原模型为核化模型,还原活化能Er=55.53KJ/mol.CeO_2对铬铬系中变催化剂还原性能的改善,在CeO_2含量为3wt％时最为显著,它既起结构型促进作用,也起电子型促进作用。提出了CeO_2促进还原的机理。
The reduction process of Fe2O3 in ( Fe, Cr)3O4 was st -udied by using TPR, TG and DTA.The results indicated that the basicreduction process of Fe2O3 is Fe2O3─→Fe3O4─→Fe, the reducing activation energy is 55. 53kJ/mol. Also, the effect of CeO2 in (Fe,Cr)3O4 was studied,The results showed that there is an optimal content value of CeO2 (3wt%) for improving the catalyst's reduction process. CeO2 played not only a role of structral promoted-catalysis, but also a role of electronic promoted-catalysis.A mechanism was given in this paper, by which CeO2 improvs the reduction process of ( Fe, Or) 3O4.
基金
山西省自然科学基金项目
关键词
氧化铈
还原
铁
铬
变催化剂
cerium dioxide
catalysis
water-gas shift reaction
reduction process
