METHANE ACTIVATION BY THE LANTHANIDE OXIDES.

Article abstract of DOI:10.1021/j100314a032

The catalytic production of gas-phase methyl radicals from methane over the lanthanide oxides was measured by using a matrix isolation electron spin resonance (MIESR) technique. The results show that metal centers with multiple stable oxidation states are not a requirement for activity. The oxide with the greatest activity per gram was hydrothermally treated La//2O//3, which was ca. 5 times more active than the next highest oxide. Hydrothermally treated La//2O//3 and Sm//2O//3 have the largest activities per square meter. Results obtained in a conventional flow reactor for selected oxides indicate that the CH//4 conversions per square meter are in the order Nd//2O//3 greater than La//2O//3 greater than Sm//2O//3 greater than Dy//2O//3 greater than CeO//2. Oxidative coupling of CH//4 results in C// 2H//6 and C//2H//4 (C//2 compounds), and the combined C//2 yields follow the same order with Dy//2O//3 VM GT TH CeO//2.