An EXAFS Study of a Highly Dispersed Rh/Al2O3 Catalyst
The X-ray absorption spectrum of the Rh K-edge of a highly dispersed reduced Rh/Al2O3 catalyst shows EXAFS oscillations due to Rhodium-Rhodium nearest neighbors. Adsorption of CO at room temperature on the reduced catalyst significantly decreases the amplitude of the EXAFS oscillations. This implies that CO adsorption on very small metal crystallites leads to a disruption of a significant number of the Rhodium-Rhodium metallic bonds.
These results show that the Rh in this system is not monatomically dispersed but is in the form of very small crystallites whose structure is disrupted by the adsorption of CO.
KeywordsCatalysis Carbonmonoxide Dium Chemisorption Rhodium
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