In situ XAS with high-energy resolution: the changing structure of platinum during the oxidation of carbon monoxide

Singh, J., Tromp, M., Safonova, O. V., Glatzel, P. and van Bokhoven, J. A. (2009) In situ XAS with high-energy resolution: the changing structure of platinum during the oxidation of carbon monoxide. Catalysis Today, 145 (3-4), 300-306. (doi:10.1016/j.cattod.2008.11.019).

Abstract

The catalytically active speci0920-5861es during the oxidation of carbon monoxide over a real alumina-supported
platinum catalyst under atmospheric pressure are determined by combining in situ high-energy
resolution fluorescence detection X-ray absorption spectroscopy (HERFD XAS) at the Pt L3 edge and
kinetic measurements. Catalysts were prepared by incipient wetness impregnation.

The oxidation of carbon monoxide occurred in two distinctive regimes, a high-activity regime and a low-activity regime, which have high and low rates of reaction respectively. In the low-activity region, the catalyst is poisoned by carbon monoxide, limiting the dissociative adsorption of oxygen. In the high-activity
regime, all CO is desorbed from the surface, increasing the rate of reaction. The low carbon monoxide concentration enables oxygen to react to the surface in this reaction regime generating a more reactive surface.

HERFD showed that different phases are active depending on the reaction conditions in nanosized catalyst particles.

This record has no associated files available for download.

Contributors

Download statistics