In Situ Observation of Rh-CaTiO3 Catalysts during Reduction and Oxidation Treatments by Transmission Electron Microscopy

Scanning transmission electron microscopy of high-surface-area Rh-doped CaTiO3 powder, conducted near atmospheric pressure at elevated temperature (250–700 °C) by means of an electron-transparent gas cell with a sample heater, provides evidence for both cyclical precipitation–dissolution of Rh nanoparticles in response to redox cycling of the ambient gas and sintering of the powder.