摘要
采用共沉淀法制备了水溶性聚合物修饰的苯选择加氢制环己烯Ru-Zn催化剂,并用X射线衍射、透射电镜、X射线能量色散谱、X射线光电子能谱和氮气物理吸附等对加氢后催化剂进行了表征.结果表明,水溶性聚合物的种类和聚乙二醇-20000(PEG-20000)的用量对Ru-Zn催化剂微晶尺寸有显著影响.在Zn SO4存在下,随着Ru-Zn催化剂Ru微晶尺寸增加,苯转化率降低,环己烯最高收率则呈火山型变化趋势.用0.4 g PEG-20000修饰的Ru-Zn催化剂[m(PEG-20000)∶m(Ru)=0.2]Ru的微晶尺寸为4.8 nm,环己烯最高收率为62.2%.Ru微晶尺寸影响催化剂表面的Zn/Ru原子比,进而影响Ru-Zn催化剂性能.
Ru-Zn catalysts modified by water soluble polymers were prepared by a precipitation method. The catalysts after hydrogenation were characterized by X-ray diffraction,transmission electron microscopy,energy dispersive spectroscopy,X-ray photoelectron spectroscopy and N2 physisorption. It was found that the type of water-soluble polymers and the dosage of PEG-20000 imposed a remarkable effect on the particle size of Ru.With the Ru particle size in Ru-Zn catalysts increasing,benzene conversion decreased,and the maximum cyclohexene yield showed a volcanic-type variation tendency. When the Ru particle size of the Ru-Zn catalyst modified by 0. 4 g PEG[m（ PEG-20000） ∶ m（ Ru） = 0. 2] was 4. 8 nm,a maximum cyclohexene yield of62. 2% was obtained on this catalyst. The Ru particle size could produce an effect on the Zn / Ru atomic ratio on the catalyst surface,which was the primary reason why the Ru particle size could affect the performance of Ru-Zn catalysts.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第10期1969-1976,共8页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:21273205,U1304204)
河南省博士后科研项目(批准号:2013006)资助~~
关键词
苯
选择加氢
环己烯
水溶性聚合物
粒径效应
Benzene
Selective hydrogenation
Cyclohexene
Water-soluble polymer
Particle size effect
