Sintering inhibition mechanism of platinum supported on ceria-based oxide and Pt-oxide-support interaction

Sintering inhibition mechanism of Pt in Pt/ceria-based oxide catalyst under oxidizing condition at high temperature was studied by several analysis techniques. Pt in a Pt/ceria-based oxide catalyst did not sinter after aging treatment at 800 degrees C in air, but did sinter in a Pt/Al2O3 catalyst. Using X-ray absorption analysis, we found that the Pt-O-Ce bond (i.e., the Pt-oxide-support interaction) acted as an anchor and inhibited the sintering of Pt particles on ceria-based oxide. As a result of further systematic investigation on various Pt catalysts, clearly there was an excellent correlation between the strength of the Pt-oxide-support interaction and the electron density of oxygen in the support oxide. The sintering inhibition effect on Pt can be controlled by the electron density of oxygen in the support through the Pt-oxide-support interaction. (c) 2006 Elsevier Inc. All rights reserved.