Ruthenium Diffusion on Different CeO₂ Surfaces: Support Shape Effect

Ceria (CeO2) is often used to support transition or noble metal catalysts providing enhanced catalytic properties. The main reason is that CeO2 possesses high oxygen storage capacity and oxygen mobility, arising from the easy switch between the Ce +4 and Ce +3 oxidation states with formation and elimination of oxygen vacancies from different surfaces. In the last decade, substantial efforts have been devoted to understanding the facet-dependent chemical reactivity of CeO2 nanoparticles. It has been found that tailoring CeO2 into different morphologies such as rods or cubes and exposing distinct facets ({100}, {110}, or {111}) can lead to considerable improvement in many redox related catalytic performances, compared to thermally stable octahedral CeO2 particles Recently, CeO2 supported ruthenium-based catalysts have attracted much attention in the catalytic combustion of chlorobenzene, low-temperature CO2 methanation and ammonia synthesis. In this work, CeO2 nanorods (NR), nanocubes (NC) and nanoctahedra (NO) were selected to prepare supported ruthenium catalysts in order to investigate the correlation between the morphology and exposed crystal plane of nanoscale CeO2 support and their lowtemperature CO oxidation activity, which can deepen our understanding of the interactions between Ru and CeO2 at the interfaces.