Combined (S)TEM-FIB Insight into the Influence of the Preparation Method on the Final Surface Structure of a Co3O4/La-Modified-CeO2 Washcoated Monolithic Catalyst

A detailed structural and chemical characterization study has been performed, both at the micrometer and nanometer scale levels, throughout the different steps of preparation of a catalytic device consisting in Co3O4/La-modified-CeO2/Al2O3 powders washcoated onto a honeycomb-type cordierite monolith. High-resolution transmission electron microscopy (HREM) images obtained from the initial catalyst powder allowed us identifying the formation of 50–100 nm crystallites of a Co3O4 phase in contact with bundles of much smaller CeO2nanocrystallites. For the catalytic device, backscattered electron images and X-ray energy dispersive spectroscopy (XEDS) elemental maps acquired in a scanning electron microscope (SEM) provided quantitative estimate of key parameters of the washcoated monolith as the thickness of the catalyst coating and the percentage of the monolith internal surface covered by the active catalytic components. Electron transparent cross-section lamellae of the monolith coating were also prepared by ...