Quantitative Contrast Evaluation of an Industry‐Style Rhodium Nanocatalyst with Single Atom Sensitivity
Quantitative Contrast Evaluation of an Industry‐Style Rhodium Nanocatalyst with Single Atom Sensitivity
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单原子灵敏度工业型铑纳米催化剂的定量对比评价
DOI：
10.1002/cctc.201000396
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发表时间：
2011
期刊：
影响因子：
4.5
通讯作者：
C. Kisielowski
中科院分区：
文献类型：
--
作者：
P. Specht;R. Gulotty;David G. Barton;R. Cieslinski;S. Rozeveld;Joo H. Kang;O. Dubon;C. Kisielowski
像差校正电子显微镜为材料表征开辟了新方法。在催化剂研究中，它将能够观察单原子排列，例如催化剂颗粒上助催化剂原子的位置。然而，必须开发定量程序来解决由于光束样本相互作用和不相干仪器像差而导致的动态对比度变化。我们证明，在低加速电压 (80 kV) 下，碰撞损伤受到抑制，残余强度波动可归因于声子的存在，导致 3D 低频原子位移。对于铑[110]取向的颗粒，发现催化剂是长径比约为0.2、表面粗糙度为±1 原子的片晶。观察单个表面原子需要最小化声子引起的运动。
Aberration‐corrected electron microscopy opens new ways for material characterization. In catalyst research it will enable the observation of single atom arrangements, such as the location of promoter atoms on catalyst particles. However, quantitative procedures must be developed to account for dynamic contrast changes resulting from beam‐sample interactions and incoherent instrument aberrations. We demonstrate that at low acceleration voltage (80 kV), for which knock‐on damage is suppressed, the residual intensity fluctuations can be attributed to the presence of phonons resulting in 3D low frequency atom displacements. For rhodium [110] oriented particles it was found that the catalysts are platelets with an aspect ratio of about 0.2 and a surface roughness of ±1 atom. Observation of single surface atoms requires minimization of phonon‐induced motion.