Decomposition of Methanol, Acetaldehyde, and Acetone on Supported Rhodium Catalysts.

The decomposition processes for methanol, acetaldehyde, and acetone over supported rhodium catalytic films have been investigated using infrared spectroscopy. An interesting support effect was observed for methanol decomposition with methane being the primary product over RhTiO2 and dimethyl ether being formed over RhA12O3. In the latter case the Al2O3 support was the active catalyst. For acetaldehyde decomposition the principle products were methane and acetone for both support rhodium catalysts. Acetone decomposition produced only inactive carbon with no other infrared-detectable surface species. It is possible that a metallic rhodium gem dicarbonyl adsorbate was produced during the decomposition of acetaldehyde over RhAl2O3. Previous observations of the rhodium gem dicarbonyl species have referred to dispersed Rh ions.