Abstract
In the case of Li-promoted MgO two different mechanisms for regeneration of the active site are found when varying the temperature between 550 and 700 °C. Propane titration showed that the active site is deactivated through formation of hydroxyl groups that are stable at 550 °C and below in absence of oxygen. On the contrary at 700 °C, propane pulses resulted in hydrocarbon activation, accompanied by evolution of water molecules. In addition, simultaneous evolution of hydrogen molecules pulsing propane indicate that ODH of propane follows a mixed heterogeneous–homogeneous radical chemistry. No COx was observed while pulsing propane at both temperatures. Moreover COx molecules were not detected even during catalyst regeneration by pulsing oxygen showing that Li/MgO materials are not affected by coke formation. Formation of COx molecules seems to be feasible exclusively by co-feeding propane and oxygen.
Original language | English |
---|---|
Pages (from-to) | 19-26 |
Number of pages | 8 |
Journal | Catalysis today |
Volume | 145 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - 2009 |
Keywords
- Li-promoted MgO
- Oxidative dehydrogenation/cracking of propane
- De-hydroxylation reaction
- Active site regeneration
- 2024 OA procedure