Novel approaches for the improvement of selectivity in the oxidative activation of light alkanes

Selectivity is the key parameter for the practical application of oxidative activation of light alkanes, improving energy and raw materials utilisation efficiency and reducing CO2 formation and emission. The intrinsic process complexity and the catalyst multifunctionality imply the need of a close control of many parameters (active centres nature, reactant composition, reaction mechanism, etc.) to improve the selectivity. Novel approaches to get this goal along three complementary directions, say: oxide nanocatalysts preparation by non-conventional routes (to tune the nature of the active centre), oxidant selection (to avoid overoxidation), and catalyst arrangement (to take advantage of the reaction mechanistic features), are presented and discussed by means of representative examples of their application. These include ODH of propane on nanosized molybdates, ODH of ethane with CO2 on ceria- and MCM-41-based catalysts, and selective oxidation of light alkanes to unsaturated oxygenates over transition metal substituted MCM-41 catalysts.