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Oxygen precursor to the reactive intermediate in methanol synthesis by Cu-ZSM-5

Smeets, Pieter J. and Hadt, Ryan G. and Woertink, Julia S. and Vanelderen, Pieter and Schoonheydt, Robert A. and Sels, Bert F. and Solomon, Edward I. (2010) Oxygen precursor to the reactive intermediate in methanol synthesis by Cu-ZSM-5. Journal of the American Chemical Society, 132 (42). pp. 14736-14738. ISSN 0002-7863. PMCID PMC2974621. https://resolver.caltech.edu/CaltechAUTHORS:20180612-135652810

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Abstract

The reactive oxidizing species in the selective oxidation of methane to methanol in oxygen activated Cu-ZSM-5 was recently defined to be a bent mono(μ-oxo)dicopper(II) species, [Cu_2O]^(2+). In this communication we report the formation of an O_2-precursor of this reactive site with an associated absorption band at 29,000 cm^(-1). Laser excitation into this absorption feature yields a resonance Raman (rR) spectrum characterized by ^(18)O_2 isotope sensitive and insensitive vibrations, νO-O and νCu-Cu, at 736 (Δ^(18)O_2 = 41 cm^(-1)) and 269 cm^(-1), respectively. These define the precursor to be a μ-(η^2:η^2) peroxo dicopper(II) species, [Cu_2(O_2)]^(2+). rR experiments in combination with UV-vis absorption data show that this [Cu_2(O_2)]^(2+) species transforms directly into the [Cu_2O]^(2+) reactive site. Spectator Cu^+ sites in the zeolite ion-exchange sites provide the two electrons required to break the peroxo bond in the precursor. O_2-TPD experiments with ^(18)O_2 show the incorporation of the second ^(18)O atom into the zeolite lattice in the transformation of [Cu_2(O_2)]^(2+) into [Cu_2O]^(2+). This study defines the mechanism of oxo-active site formation in Cu-ZSM-5.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1021/ja106283uDOIArticle
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2974621/PubMed CentralArticle
https://pubs.acs.org/doi/suppl/10.1021/ja106283uPublisherSupporting Information
ORCID:
AuthorORCID
Hadt, Ryan G.0000-0001-6026-1358
Solomon, Edward I.0000-0003-0291-3199
Additional Information:© 2010 American Chemical Society. Received July 15, 2010. P.J.S. acknowledges the IWT, FWO, and K.U.Leuven for graduate and postdoctoral fellowships, and J.S.W. acknowledges the NIH for a traineeship. R.G.H. is a Gerhard Casper Stanford Graduate Fellow. This research was supported by the GOA and the Long Term Structural Funding-Methusalem Funding by the Flemish Government (R.A.S., B.F.S.) and by NIH Grant DK-31450 (E.I.S.).
Funders:
Funding AgencyGrant Number
Agency for Innovation by Science and Technology (IWT)UNSPECIFIED
Fonds Wetenschappelijk Onderzoek (FWO)UNSPECIFIED
Katholieke Universiteit LeuvenUNSPECIFIED
NIH Predoctoral FellowshipUNSPECIFIED
Stanford UniversityUNSPECIFIED
NIHDK31450
Issue or Number:42
PubMed Central ID:PMC2974621
Record Number:CaltechAUTHORS:20180612-135652810
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20180612-135652810
Official Citation:Oxygen Precursor to the Reactive Intermediate in Methanol Synthesis by Cu-ZSM-5 Pieter J. Smeets, Ryan G. Hadt, Julia S. Woertink, Pieter Vanelderen, Robert A. Schoonheydt, Bert F. Sels, and Edward I. Solomon Journal of the American Chemical Society 2010 132 (42), 14736-14738 DOI: 10.1021/ja106283u
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:87017
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:12 Jun 2018 21:13
Last Modified:03 Oct 2019 19:51

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