Electron tomography of Pt nanocatalyst particles and their carbon support

Abstract

Industrial nanocatalysts usually comprise crystalline particles of high atomic number that have sizes of between 1 and 20 nm and are supported or embedded in a lower atomic number matrix. The physical characterisation of the three-dimensional shapes and sizes of such particles can now be carried out using high-angle annular darkfield electron tomography. The spatial distribution of the particles with respect to their matrix is an issue of paramount importance for their performance as catalysts. Here, we show experimental electron tomography results from platinum particles dispersed in a carbon support. We show that both the high and the low atomic number regions of the same region of a sample can be characterised by using a combination of high and low angle annular dark field and bright field signals. © 2006 IOP Publishing Ltd.