Jan Höcker, Tomáš Duchoň, Kateřina Veltruská, Vladimír Matolín, Jens Falta, Sanjaya D. Senanayake and J. Ingo Flege.
The Journal of Physical Chemistry C (2016) 120, 4895−4901.
A novel and simple method is presented for the preparationof a well-defined CeO2(100) model system on Cu(111) based on theadjustment of the Ce/O ratio during growth. The method yieldsmicrometer-sized, several nanometers high, single-phase CeO2(100) islandswith controllable size and surface termination that can be benchmarkedagainst the known (111) nanostructured islands on Cu(111). Furthermore,we demonstrate the ability to adjust the Ce to O stoichiometry from CeO2(100) (100% Ce4+) to c-Ce2O3(100) (100% Ce3+), which can be readily recognized by characteristic surfacereconstructions observed by low-energy electron diffraction. The discovery of the highly stable CeOx(100) phase on ahexagonally close packed metal surface represents an unexpected growth mechanism of ceria on Cu(111), and it provides novelopportunities to prepare more elaborate models, benchmark surface chemical reactivity, and thus gain valuable insights into theredox chemistry of ceria in catalytic processes.
