Abstract
The mechanistic pathways of direct oxidation of methanol to formaldehyde by N2O were theoretically investigated by means of density functional theory (DFT) over an extra framework species in ZSM-5 zeolite represented by a [Si6Al2O9H14]2–[Fe]2+ cluster model. The catalytic reactivity of these species is compared with that of mononuclear Fe1+ and (FeO)1+ sites in ZSM-5 investigated in our earlier work at the same level of theory (J. Catal.2011, 282, 191). The formation of the grafted species including methoxy on the [Fe]2+ site was calculated to be thermodynamically more stable than on the [FeO]1+ site and less stable than on the [Fe]1+ site. The order of activation barrier values of a critical step, proton transfer from grafted methoxy to form formaldehyde and water, on these sites is as follows: [Fe]1+ > [Fe]2+ ≫ [FeO]1+. The calculated vibrational frequencies for grafted species on the iron site on the surface are in good agreement with the experimental values.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.