| Abstract
| - Vanadium-incorporated MCM-41 type catalytic materials, which were synthesized by a direct hydrothermalsynthesis procedure, showed very high activity and high selectivity in the production of ethylene from ethanolin an oxidative process. Ethylene selectivity showed a significant increase with an increase in temperatureover 300 °C, while relatively high acetaldehyde selectivities were observed at lower temperatures. An ethyleneyield value of 0.66 obtained at 400 °C with an O2/ethanol feed ratio of 0.5 was beneficial from the point ofview that these results might open a new pathway for the production of ethylene from a nonpetroleumenvironmentally friendly feedstock, namely, bioethanol. The optimum V/Si ratio of the catalyst, which gavethe maximum ethylene yield, was found to be around 0.04. Experimental results showing the formation ofacetaldehyde and not showing the formation of ethylene in the absence of gas-phase oxygen and the catalystdeactivation observed in such conditions suggested a redox mechanism involving the surface lattice oxygenof the catalyst in acetaldehyde production, while the involvement of adsorbed oxygen was concluded to takeplace in the formation of ethylene.
|
