274834 Reaction of Methylene On α-Fe2O3(10-12)

Thursday, November 1, 2012: 10:42 AM
321 (Convention Center )
Yujung Dong and David F. Cox, Chemical Engineering, Virginia Tech, Blacksburg, VA

Methylene, :CH2, has been produced via the thermal dissociation of CH2I2 to examine the reaction of this simple carbene on α-Fe2O3(10-12). Thermal desorption experiments indicate the existence of multiple reaction pathways for surface methylene depending on the stoichiometry of the surface. The reaction of methylene on the nearly-stoichiometric surface produces CO2 and CO as the primary carbon-containing products, formed via the consumption of surface lattice oxygen. As the surface becomes reduced, formaldehyde, H2CO, and ethylene, CH2=CH2 production become evident, while the production of CO2 and CO decrease. Since the stoichiometric α-Fe2O3(10-12) surface exposes cations and anions with a single coordination vacancy, the decrease in oxygen-containing products with surface reduction is attributed to a decrease in the availability of coordinately-unsaturated surface oxygen anions. The selectivity change to coupling products for the most reduced surfaces is attributed to the appearance of surface cations with multiple coordination vacancies associated with the loss of surface oxygen.

Extended Abstract: File Not Uploaded
See more of this Session: Fundamentals of Oxide Catalysis
See more of this Group/Topical: Catalysis and Reaction Engineering Division