3rd Workshop on the Simultaneous Combination of Spectroscopies with X-ray Absorption, Scattering and Diffraction Techniques

In situ X-ray absorption investigation of the effect of Sm2O3 and CeO2 promoters on the structure of Rh/Al2O3 catalysts in methane steam reforming

5 Jul 2012, 10:30

1h 30m

Main Hall HG E

Poster contribution Catalysis Poster Session

Speaker

Ms Renata Bessa Duarte (ETH Zurich)

Description

The role of Sm2O3 and CeO2 promoters on the structural properties and catalytic behavior of 0.5 wt% Rh/xSm2O3-yCeO2-Al2O3 catalysts during methane steam reforming (MSR) was investigated by in situ X-ray absorption spectroscopy and other characterization methods. Catalytic tests were performed at 773 and 1033 K. The combination of XAS measurements with mass spectrometer provided a way to analyze conversion and structure simultaneously. The effect of the addition of Sm2O3 and CeO2 on the catalytic behavior of Rh/Al2O3 catalysts was revealed by changes on the structure properties of Rh particles. The high activity observed for the studied Rh catalysts during reaction was mainly attributed to the high dispersion of the active phase. The improvement in the activity and stability of promoted catalysts is due to the greater Rh-support interaction, which inhibited Rh oxidation and the sintering of the Rh particles, thus maintaining the high dispersion during the drastic reaction conditions. The EXAFS experiments clearly illustrate the alteration of the topology and therefore the lack of stability of rhodium particles when supported in unpromoted alumina.