稀土对Ni-ZnO基脱硫催化剂反应性能的影响机制

发布时间：2019-02-12 18:44

【摘要】：为考察La、Ce对还原后的Ni-ZnO催化剂电子结构的调变作用,模拟工业条件对催化剂进行高压还原,对还原后的催化剂进行Ar离子刻蚀-XPS表征。结果表明,还原后的催化剂中以Ni 0为主,La不会被还原,Ce~(4+)被还原为Ce~(3+)。La~(3+)和Ce~(3+)在催化剂外表面富集,并与Ni之间存在相互作用,电子由Ni偏向La~(3+)和Ce~(3+),导致Ni的电子不饱和度增加,从而增强其对硫化物中孤对电子的吸附,使Ni-ZnO催化剂脱硫活性增强。但由于La、Ce与Ni-ZnO的电子配位结构存在明显差别,使用Ce改性的催化剂,在相同脱硫率下,汽油产品辛烷值较高;特别是当催化剂中Ce的质量分数为3.0%时,汽油的平均硫质量分数仅为5.1μg/g,与原料相比,研究法辛烷值增加0.3个单位。
[Abstract]:In order to investigate the effect of La,Ce on the electronic structure of reduced Ni-ZnO catalyst, the catalyst was reduced at high pressure under simulated industrial conditions, and the reduced catalyst was characterized by Ar ion etch-XPS. The results showed that Ni _ 0 was the main catalyst, La would not be reduced, Ce~ (4) was reduced to Ce~ (3), La~ (3) and Ce~ (3) were enriched on the outer surface of the catalyst, and there was interaction between Ce~ (4) and Ni. The electron bias from Ni to La~ (3) and Ce~ (3) leads to an increase in the electron unsaturation of Ni, which enhances the adsorption of isolated electrons in sulfides and enhances the desulfurization activity of the Ni-ZnO catalyst. However, due to the obvious difference in the electronic coordination structure between La,Ce and Ni-ZnO, the octane number of gasoline products is higher when the catalyst modified by Ce is used in the same desulfurization rate. In particular, when the mass fraction of Ce in the catalyst is 3.0, the average sulfur content of gasoline is only 5.1 渭 g / g. Compared with the raw material, the octane number of the research method increases by 0.3 units.
【作者单位】：中国石化石油化工科学研究院;
【基金】：中国石油化工股份有限公司科技开发项目(ST114007)资助
【分类号】：TE624.9

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