STEM Image Analysis Using LAT Image Processing

Abstract

In order to develop catalysts it is important to characterize the system in terms of particle size and size distribution. TEM or STEM are used as the state-of-the-art methods. In this study monodispersed Pt3Co alloy nanoparticles supported on carbon black (CB) prepared by the nanocapsule method are investigated and the results are compared with a commercially available Pt3Co/C catalyst system. To avoid the obstacles of conventional bright-field TEM or STEM regarding the image analysis, an advanced computerized image processing procedure is introduced. The so-called local adaptive threshold (LAT) is a method for a precise determination of particle diameter and size distribution in the subnanometer scale. The results demonstrate the advantage of a completely computerized particle evaluation as compared to a conventional particle analysis.