摘要
采用共沉淀法制备了一系列不同Zn负载量的Ru-Zn催化剂.XRD和XPS结果表明,催化剂中的Zn大部分以ZnO形式存在,在加氢过程中催化剂表面的ZnO可以与浆液中的Zn2+形成碱式硫酸锌盐.随催化剂中Zn负载量的增加,碱式硫酸锌盐的量也增加,这导致催化剂活性降低和环己烯选择性升高.当Zn负载量为8.6%时,加氢后碱式硫酸锌盐在Ru-Zn催化剂表面上接近单层分散态.单层分散型Ru-Zn催化剂催化性能最佳,该催化剂在140oC,5MPaH2下和0.6mol/L硫酸锌溶液中预处理22h后,反应20min,苯转化率84.4%时,环己烯选择性为69.8%.
A series of Ru-Zn catalysts with different Zn loadings were prepared by co-precipitation. X-ray diffraction and X-ray photoelectron spectroscopy results showed that a large part of the Zn in the Ru-Zn catalysts were present in the form of ZnO and the ZnO on the catalyst surface could react with ZnSO4 in the slurry to form a basic zinc sulfate salt during hydrogenation. The content of the basic salt increased with an increase in the Zn loading of the catalysts. This resulted in a decrease in catalyst activity and an increase in selectivity for cyclohexene. When the Zn loading was 8.6%,the basic salt dispersion was close to monolayer dispersion on the catalyst surface. When the catalysts were pretreated in the presence of 0.6 mol/L ZnSO4 solution at 140 °C and at 5 MPa H2,a cyclohexene selectivity of 69.8% and a benzene conversion of 84.4% was achieved after 20 min.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第2期224-230,共7页
基金
教育部科学技术研究重点项目(202093)
关键词
单层分散型
钌
锌
苯
选择加氢
环己烯
monolayer dispersion
ruthenium
zinc
benzene
selective hydrogenation
cyclohexene
