| AVS 62nd International Symposium & Exhibition | |
| Atom Probe Tomography Focus Topic | Monday Sessions |
| Session AP+AS+MC+MI+NS-MoM |
| Session: | Atom Probe Tomography of Nanomaterials |
| Presenter: | Katja Eder, The University of Sydney, Australia |
| Authors: | K. Eder, The University of Sydney, Australia P.J. Felfer, The University of Sydney, Australia J.M. Cairney, The University of Sydney, Australia |
| Correspondent: | Click to Email |
Pt nanoparticles are commonly used as catalysts in fuel cells. There are a lot of factors which influence the activity of a catalyst, including the surface structure and geometry [1], d-band vacancy of the metal catalyst [2], the type of metal oxide support [3] and the oxidation state of the surface [4]. It is not yet fully understood in which way these factors influence the activity of the catalyst, since it is experimentally very difficult to get atomic scale information about the distribution of the atoms within such particle with conventional methods like transmission electron microscopy (TEM), scanning electron microscopy (SEM), scanning tunnelling microscopy (STM) and others. Models available which try to explain the structure-activity relationships therefore vary widely and there is much debate in the scientific literature about the underlying mechanisms of catalysis. For this reason it is crucial to conduct more research with methods that are able to obtain chemical information with a resolution on the atomic scale. In the past few years atom probe tomography (APT) has successfully been used in several studies to analyse nanoparticles [4-6]. APT provides a 3D reconstruction of the original specimen, which gives information about the chemical composition and the microstructure at a very high resolution. This method will enable us to have a closer look at the surface and interfaces as well as the composition of individual nanoparticles and solute atoms. In this talk we will present APT results of Pt nanoparticles, describing our efforts to prepare specimens with a reasonable yield and improved throughput compared to earlier studies, as well as some of the approaches used to overcome the difficulties that this challenge presents.
[1] A.R. Tao, S. Habas, P. Yang, Small, 4 (2008) 310-325.
[2] M.-K. Min, J. Cho, K. Cho, H. Kim, Electrochimica Acta, 45 (2000) 4211-4217.
[3] T. Akita, M. Kohyama, M. Haruta, Accounts of chemical research, (2013).
[4] T. Li, E.A. Marquis, P.A.J. Bagot, S.C. Tsang, G.D.W. Smith, Catalysis Today, 175 (2011) 552-557.
[5] Y. Xiang, V. Chitry, P. Liddicoat, P. Felfer, J. Cairney, S. Ringer, N. Kruse, Journal of the American Chemical Society, 135 (2013) 7114-7117.
[6] D.J. Larson, A.D. Giddings, Y. Wu, M.A. Verheijen, T.J. Prosa, F. Roozeboom, K.P. Rice, W.M.M. Kessels, B.P. Geiser, T.F. Kelly, Ultramicroscopy, (2015).