Open Access
Oxygen precursor to the reactive intermediate in methanol synthesis by Cu-ZSM-5
Pieter Vanelderen,Pieter J. Smeets,Ryan G. Hadt,Julia S. Woertink,Robert A. Schoonheydt,Bert F. Sels,Edward I. Solomon +6 more
- Vol. 242
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TLDR
The mechanism of oxo-active site formation in Cu-ZSM-5 is defined and the formation of an O(2)-precursor of this reactive site with an associated absorption band at 29,000 cm(-1) is reported.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(2)O](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(2)O](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(2)O](2+). This study defines the mechanism of oxo-active site formation in Cu-ZSM-5.read more
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Journal ArticleDOI
Copper Active Sites in Biology
Edward I. Solomon,David E. Heppner,Esther M. Johnston,Jake W. Ginsbach,Jordi Cirera,Munzarin F. Qayyum,Matthew T. Kieber-Emmons,Christian H. Kjaergaard,Ryan G. Hadt,Li Tian +9 more
TL;DR: This review presents in depth discussions of all these classes of Cu enzymes and the correlations within and among these classes, as well as the present understanding of the enzymology, kinetics, geometric structures, electronic structures and the reaction mechanisms these have elucidated.
Journal ArticleDOI
Recent advances in heterogeneous selective oxidation catalysis for sustainable chemistry
TL;DR: Recent advances in the development of new catalytic materials or novel catalytic systems for challenging oxidation reactions, which are important from the viewpoint of green and sustainable chemistry and still remain challenging, are summarized.
Journal ArticleDOI
Dynamic multinuclear sites formed by mobilized copper ions in NO x selective catalytic reduction.
Christopher Paolucci,Ishant Khurana,Atish A. Parekh,Sichi Li,Arthur J. Shih,Hui Li,John R. Di Iorio,Jonatan D. Albarracin-Caballero,Aleksey Yezerets,Jeffrey T. Miller,W. Nicholas Delgass,Fabio H. Ribeiro,William F. Schneider,Rajamani Gounder +13 more
TL;DR: It is demonstrated that under reaction conditions, mobilized Cu ions can travel through zeolite windows and form transient ion pairs that participate in an oxygen (O2)–mediated CuI→CuII redox step integral to SCR.
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Chemistry with Methane: Concepts Rather than Recipes
TL;DR: Four seemingly simple transformations related to the chemistry of methane are addressed from mechanistic and conceptual points of view: metal-mediated dehydrogenation to form metal carbene complexes, the hydrogen-atom abstraction step in the oxidative dimerization of methane, the mechanisms of the CH(4)→CH(3)OH conversion, and the initial bond scission.
Journal ArticleDOI
Reactivity of Surface Species in Heterogeneous Catalysts Probed by In Situ X-ray Absorption Techniques
TL;DR: (Article begins on next page)
References
More filters
Journal ArticleDOI
Copper Active Sites in Biology
Edward I. Solomon,David E. Heppner,Esther M. Johnston,Jake W. Ginsbach,Jordi Cirera,Munzarin F. Qayyum,Matthew T. Kieber-Emmons,Christian H. Kjaergaard,Ryan G. Hadt,Li Tian +9 more
TL;DR: This review presents in depth discussions of all these classes of Cu enzymes and the correlations within and among these classes, as well as the present understanding of the enzymology, kinetics, geometric structures, electronic structures and the reaction mechanisms these have elucidated.
Journal ArticleDOI
Recent advances in heterogeneous selective oxidation catalysis for sustainable chemistry
TL;DR: Recent advances in the development of new catalytic materials or novel catalytic systems for challenging oxidation reactions, which are important from the viewpoint of green and sustainable chemistry and still remain challenging, are summarized.
Journal ArticleDOI
Dynamic multinuclear sites formed by mobilized copper ions in NO x selective catalytic reduction.
Christopher Paolucci,Ishant Khurana,Atish A. Parekh,Sichi Li,Arthur J. Shih,Hui Li,John R. Di Iorio,Jonatan D. Albarracin-Caballero,Aleksey Yezerets,Jeffrey T. Miller,W. Nicholas Delgass,Fabio H. Ribeiro,William F. Schneider,Rajamani Gounder +13 more
TL;DR: It is demonstrated that under reaction conditions, mobilized Cu ions can travel through zeolite windows and form transient ion pairs that participate in an oxygen (O2)–mediated CuI→CuII redox step integral to SCR.
Journal ArticleDOI
Lewis acids as catalysts in oxidation reactions: from homogeneous to heterogeneous systems.
TL;DR: This review is focused on the use of solid Lewis acids to promote catalytic oxidations, and the core of the review is organized to show the evolution from the simplest strategy for heterogeneizing homogeneous catalysts, to the more elaborate ones in which the active sites are part of the solid structure.
Journal ArticleDOI
Selective Oxidation of Methane by the Bis(μ-oxo)dicopper Core Stabilized on ZSM-5 and Mordenite Zeolites
TL;DR: Three lines of evidence firmly support the key role of the bis(mu-oxo)dicopper core in this selective, low-temperature hydroxylation of methane.