Atomic structure of three-layer Au/Pd nanoparticles revealed by aberration-corrected scanning transmission electron microscopy
- Univ. of Texas, Austin, TX (United States). Chemical Engineering Dept.
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
- Autonomous Univ. of Nuevo Leon, Monterrey (Mexico). Center for Innovation, Research and Development in Engineering & Technology (CIIDIT)
- Autonomous Univ. of Nuevo Leon, Monterrey (Mexico). Center for Innovation, Research and Development in Engineering & Technology (CIIDIT); Advanced Materials Research Center (CIMAV), Chihuahua (Mexico)
The study of nanomaterials can be greatly improved with the use of aberration-corrected transmission electron microscopy (TEM), which provides image resolutions at the level of 1 Å and lower. Sub-Ångström image resolution can yield a new level of understanding of the behavior of matter at the nanoscale. For example, bimetallic nanoparticles are extremely important in catalysis applications; the addition of a second metal in many cases produces much-improved catalysts. Here, we study the structure and morphology of Au/Pd bimetallic particles using primarily the high-angle annular dark-field (HAADF) imaging mode in an aberration-corrected STEM/TEM. It is well established that, when recorded under appropriate illumination and collection geometries, incoherent HAADF-STEM images are compositionally sensitive and provide direct information on atomic positions. We matched the experimental intensities of atomic columns with theoretical models of three-layer Au/Pd nanoparticles, in different orientations. Our findings indicate that the surface layer of the nanoparticle contains kinks, terraces and steps at the nanoscale. Finally, the effect of adding a second metal induces the formation of such defects, which might very likely promote the well-known improved catalytic activity of this system.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Texas, Austin, TX (United States); Autonomous Univ. of Nuevo Leon, Monterrey (Mexico)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V); National Science Foundation (NSF) (United States); Welch Foundation (United States); Texas Materials Inst. (United States); Univ. of Texas (United States)
- Contributing Organization:
- Advanced Materials Research Center (CIMAV), Chihuahua (Mexico)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1361280
- Journal Information:
- Journal of Materials Chemistry, Journal Name: Journal of Materials Chemistry Journal Issue: 21 Vol. 18; ISSN 0959-9428
- Publisher:
- Royal Society of Chemistry
- Country of Publication:
- United States
- Language:
- English
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