双氧水提前引入对铈锆固溶体老化晶粒的调控研究

在传统方法基础上,通过将双氧水提前引入以控制铈锆固溶体的老化晶粒。XRD结果表明,通过控制双氧水与Ce^(3+)摩尔比,新鲜铈锆固溶体的晶粒尺寸从10.3 nm减小至9.3 nm,老化后的晶粒尺寸从20.7 nm减小至15.2 nm。N_(2)吸附-脱附和孔径分布结果显示,其均为以狭缝孔为主的介孔材料,而通过将双氧水的加入时间前移,铈锆固溶体的孔径分布逐渐向小孔处聚集(≤5 nm),其老化后的比表面积衰减率明显更低。综上所述,双氧水的提前引入对铈锆固溶体老化后的晶粒和织构性质具有显著的调控作用。因此,本文对双氧水调控机制的研究具有重要的实用价值。

Comparative Study on Oxidative Desulfurization of FCC Gasoline by Ce^(4+) Compound and H_2O_2

This article describes two kinds of model oil samples made of a benzothiophene/octane mixture and a 2-me- thylthiophene/octane mixture. Furthermore, this paper investigates the oxidative desulfurization selectivity and reaction efficiency when Ce4+ compound and H2O2 having identical electron equivalent weight were used as oxidants. The test re- sults showed that the two kinds of oxidants were more effective to remove benzothiophene in the model oil samples. For oxidative desulfurization of 2-methylthiophene, Ce4+ compound was obviously superior than H2O2. This paper by means of quantum chemistry analyses elaborates the complex formed between Ce4+ species and 2-methylthiophene and FT-IR spec- trograms of model oil samples before and after oxidation by Ce4+ compound and H2O2, respectively. The results demonstrat- ed that Ce4+ compound could remove sulfur compounds not only through oxidation reaction but also through complexation reaction.