A resonant photoemission applied to cerium oxide based nanocrystals.
Cerium 4f level occupation determines the properties of cerium oxide based catalysts in a significant way. The Ce 4f level of nanosized cerium oxide particles was investigated with the use of resonant photoelectron spectroscopy in the Ce 4d-4f photoabsorption region. A strong interaction of ceria with different additives, e.g. Pd and Sn, led to a partial Ce4+-->Ce3+ transition that was observed as a significant resonance enhancement of 4f photoemission intensity. Increases of the CO oxidation catalytic activity were observed simultaneously. The ratio of resonance enhancement of Ce photoemission intensity DCe(3+)/DCe(4+) was used to monitor Ce(3+) and Ce(4+) state occupation. The relative parameter DCe(3+)/DCe(4+) was found to be particularly useful in the case of photoemission studies of nanopowder ceria catalysts.
Matolín
V
V
Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 8, Czech Republic. matolin@mbox.troja.mff.cuni.cz
Matolínová
I
I
Sedlácek
L
L
Prince
K C
KC
Skála
T
T
D002563:Cerium / Q000737:chemistry* / Q000528:radiation effects; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D008027:Light; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D017785:Photons; D013499:Surface Properties
D046911:Macromolecular Substances; D002563:Cerium; C030583:ceric oxide