摘要
借助球差矫正扫描透射电子显微技术(Cs-STEM)对Al 2O 3负载的加氢脱硫(HDS)催化剂进行原子尺度结构表征,以期解析活性相结构与其活性之间的关系。研究表明:在Al 2O 3表面,存在金属单原子、“原子簇”及“小金属簇”等“碎片”结构,该结构利用常规透射电子显微技术(TEM)无法清晰地观察到。通过分析这些微观结构的衬度信息及结合X射线能谱的结果(STEM-EDS)可知,该“碎片”结构为分散在Al 2O 3载体表面的活性金属组分。根据不同外界条件(硫化度、温度)下HDS催化剂的原子尺度结构图可分析出,这些金属“碎片”结构随硫化程度的增加或温度的升高,逐渐发生聚集,形成具有一定几何形状的MoS 2活性相片晶。此外,将微观结构与HDS活性进行关联可知,“碎片”结构对催化剂的HDS活性具有一定的影响。
Spherical aberration corrected scanning transmission electron microscopy(Cs-STEM)was used to provide insight into the atomic-scale structure of supported hydrodesulfurization(HDS)catalysts.Atom-resolved Cs-STEM images of the HDS catalysts reveal the nano-scale“fragment”structures on Al2O3 support,such as metal single atoms,nanoparticles and metal clusters,which cannot be characterized by utilizing conventional transmission electron microscopy(TEM).Extrapolating from the contrast information of the microstructures,it is declared that the“fragment”structures are active metal components dispersed on the Al2O3 support,which is verified by the element analysis given by STEM-EDS.The atomic resolution images of supported HDS catalysts convincingly demonstrate the aggregation of the“fragment”structures are enhanced with the increase of sulfuration degree and temperature,with the formation of MoS2 active phase with certain geometrical shape.Furthermore,from the correlation between the microstructures and HDS activity,it is confirmed that the“fragment”structures have a certain effect on HDS catalyst activity.
作者
何文会
张乐
向彦娟
韩伟
户安鹏
李会峰
徐广通
郑爱国
HE Wenhui;ZHANG Le;XIANG Yanjuan;HAN Wei;HU Anpeng;LI Huifeng;XU Guangtong;ZHENG Aiguo(Research Institute of Petroleum Processing,SINOPEC,Beijing 100083,China)
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2020年第2期230-235,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家十三五重点专项基金项目(2017YFB0306603)资助。
关键词
球差矫正扫描透射电镜
加氢脱硫催化剂
微观结构
活性组分
Spherical aberration corrected scanning transmission electron microscopy(Cs-STEM)
HDS catalyst
micro-structure
active component
