Seminars Archive

Oxidation behaviour of PtRh particles

Abstract
The chemical and structural evolution of supported nano- and micro- PtRh alloy particles during oxidation have been studied by means of scanning photoelectron microscopy (SPEM) and Low Energy Electron Microscopy (LEEM). The Rh 3d and Pt 4f chemical images and microspot spectra of the micro-particles showed that Rh atoms undergo much faster oxidation than Pt atoms with well developed lateral variations in the oxidation states and coexistence of several stoichiometric and non-stoichiometric Rh and Pt oxide phases. The observed variations in the local reactivity were correlated to the complex surface morphology and following structural changes during oxidation monitored within the same micro-particle by LEEM.