摘要
分别通过透射电镜(TEM)与高角环形暗场(HAADF)方法表征了Ru/C催化剂贵金属分散性质,并对两种方法进行了对比研究;在辨别出催化剂钌粒子的基础上,提出了以平均尺寸、尺寸分布来表征贵金属分散性质的方法。结果表明:HAADF方法能够很好地辨别出炭载体上的贵金属颗粒,而TEM方法由于样品质厚的原因,存在大量钌粒子统计遗漏,因此HAADF方法表征结果更为可靠;采用HAADF方法可以得到比TEM方法更为准确的贵金属分散性质信息,并可以很大程度上解决化学吸附法与TEM方法表征催化剂贵金属分散性质的不足,从而准确地评价贵金属纳米粒子在载体上的分散情况;对于采用化学吸附法与TEM法区分载体与贵金属纳米粒子较为困难的催化剂体系,HAADF法具有更大的应用价值及优势。
The dispersion properties of noble metal in Ru/C catalyst were characterized by transmission electron microscopy(TEM)and high angle annular dark field(HAADF)methods respectively,and the two methods were compared.On the basis of identifying catalyst Ru particles,a method to characterize the dispersion properties of noble metals was proposed by means of average size and size distribution.The results show that HAADF method can distinguish the noble metal particles on the carbon support well,while a large number of Ru particles are omitted when by TEM method due to the weak mass thickness contrast of the sample,so HAADF characterization results are more reliable.Compared with TEM,the dispersion properties of catalyst are more comprehensive and accurate by HAADF method,and HAADF can overcome the shortcomings of chemical adsorption and TEM methods in characterizing the dispersion of noble metals,and can evaluate the dispersion of noble metals on carriers more intuitively and comprehensively.And HAADF method has greater application value and advantages for the catalysts that is difficult to distinguish carrier from noble metal nanoparticles by chemical adsorption and TEM methods.
作者
杨卫亚
凌凤香
刘全杰
张会成
王少军
YANG Weiya;LING Fengxiang;LIU Quanjie;ZHANG Huicheng;WANG Shaojun(Dalian Research Institute of Petroleum and Petrochemicals,SINOPEC,Dalian 116045,China)
出处
《理化检验（物理分册）》
CAS
2019年第4期232-235,239,共5页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
