An EXAFS Study of Platinum-Oxygen Bonds in the Metal-Support Interface of a Highly Dispersed Platinum/Aluminum Oxide Catalyst

Abstract

EXAFS measurements have been performed on the Pt LIII-edge of a highly dispersed (H/M~1.14) Pt/@c-Al{2}O{3} catalyst, reduced at 673 K after calcination at the same temperature. After reduction an oxidic platinum oxygen bond (2.05@9) is present with a very low average oxygen coordination number. This bond arises from a few not reduced platinum-oxide crystallites. Platinum oxygen bonds with a coordination distance of 2.65 @9 could be detected significantly due to the high quality of the EXAFS data and the use of a new data analysis procedure. These bonds are interpreted to be originating from a coordination of the interfacial platinum atoms with the oxygen ions of the support.