The interaction of CO with alumina-supported Rh has been investigated by infrared spectroscopy at 85-573 K. The oxidative disruption of Rh crystallites occurred at temperatures as low as 150 K. Desorption and readsorption of CO at low temperature demonstrated that there is a stable Rh+(CO)2 species which releases CO only at 573 K. The desorption of CO from Rh+ is mainly reductive but a certain fraction of Rh+ escapes reduction even during desorption at high temperatures, 473-573 K. The reductive agglomeration of Rh+ induced by CO occurs at 473 K. At 573 K the process is almost irreversible, which means that such large crystallites are produced that they cannot be disintegrated and oxidized again to Rh+ by CO and OH groups at room temperature. Hydrogen adsorbed on Rhx greatly retards the oxidative disruption process at low temperature which is attributed to the formation of Rh carbonyl hydride.
|Number of pages||7|
|Journal||Journal of the Chemical Society, Faraday Transactions|
|Publication status||Published - Dec 1 1990|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry