Coordination chemistry and reactivity of copper in zeolites

Vanelderen, Pieter; Vancauwenbergh, Julie; Sels, Bert F.; Schoonheydt, Robert A.

doi:10.1016/j.ccr.2012.07.008

Cited by 167 publications

(173 citation statements)

References 121 publications

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“…[25] The spectral features agree well with the isolated octahedral copper complexes observed in zeolites, in which the surrounding ligands are water or hydroxyl groups. [16,29,30] This result implies that all the Cu-SSZ-13 samples contain predominantly isolated copper species, which is in accordance with the work of Lamberti et al [31] On the basis of the results of extended X-ray absorption fine structure and UV/Vis spectroscopy, Beale et al proposed that isolated Cu 2 + is the active site for the NH 3 -SCR reaction. [20][21][22] The EPR spectra of OP-0.37 and IE-0.36 samples demonstrate the same features (Figure 3 a and b).…”

Section: Resultssupporting

confidence: 78%

Effect of the Nature and Location of Copper Species on the Catalytic Nitric Oxide Selective Catalytic Reduction Performance of the Copper/SSZ‐13 Zeolite

et al. 2013

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. (2014). Effect of the nature and location of copper species on catalytic nitric oxide selective catalytic reduction performance of the copper/SSZ-13 zeolite. ChemCatChem, 6(2), 634-639. DOI: 10.1002/cctc.201300775 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. [b] Guanna Li, [a, b] Zhaochi Feng, [a] Emiel J. M. Hensen,* [b] and Can Li*[a] IntroductionThe selective catalytic reduction (SCR) of nitrogen oxides (NO x ) with ammonia (NH 3 -SCR) is an efficient way for NO x abatement. [1][2][3] Copper-containing zeolites are one of the most active catalyst systems for the related reactions. [3][4][5][6][7][8] The most extensive studies have been performed on Cu/ZSM-5 and Cu/ BEA zeolites. Cu/BEA demonstrates excellent activity with better hydrothermal stability than does Cu/ZSM-5. [7,[9][10][11] The ion-exchanged copper-containing SSZ-13 zeolite, based on the small-pore chabazite (CHA) zeolite topology, recently demonstrated higher activity and selectivity to N 2 over a wide temperature range and better hydrothermal stability than did Cu/ ZSM-5 and Cu/BEA zeolites. [12][13][14][15][16][17] Typically, the catalytic SCR performance of the copper-containing zeolite greatly depends on the location and nature of copper species. The existence of various types of copper species in the zeolite has been proposed: Cu 2 + and Cu + monomers, [CuÀOÀCu] 2 + dimers, and CuO x clusters. [17][18][19] Isolated Cu 2 + species are usually postulated as the active sites in the SCR reaction. [20][21][22] The preparation method strongly affects the nature and speciation of the copper phase. In general, monomeric copper ions located at the cation-exchange sites dominate in ion-exchanged samples, with the fraction of [CuÀOÀ Cu] 2 + dimers typically becoming more important with increasing Cu content. [18] In contrast, precipitation usually results in the formation of a separate CuO phase located at the external zeolite surface. [17][18][19] Lobo et al. suggested that Cu 2 + ions are located in the six-membered rings of the CHA structure. [23] Combining extended X-ray absorption fine structure and in situ UV/Vis spectroscopy, Beale et al. proposed that isolated mononuclear Cu 2 + species slightly shifted toward the edge of the six-membered rings.[20] Kwak et al. reported that the location of ...

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Section: Resultssupporting

confidence: 78%

Effect of the Nature and Location of Copper Species on the Catalytic Nitric Oxide Selective Catalytic Reduction Performance of the Copper/SSZ‐13 Zeolite

et al. 2013

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“…As for formation of a second adsorbed O a high activation barrier needs to be overcome, it is predicted that these isolated site catalysts will only be active in catalytic N 2 O decomposition at high temperatures. We did not take into account the possibility that O 2 evolution may take place through surface migration and recombination of extraframework oxygens from distantly located mononuclear active sites, because such a mechanism would require the presence of two [77]. The present data also predict that the surface O atoms may differ in chemical properties during reaction at low and high temperatures.…”

Section: Discussionmentioning

confidence: 62%

Catalytic properties of extraframework iron-containing species in ZSM-5 for N2O decomposition

Pidko

Filot

et al. 2013

Journal of Catalysis

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“…In view of their novel structures and proposed reactivity, these species are prime targets for synthetic modeling studies. Another noteworthy target is the (μ-oxo)-dicopper(II) unit, which has been proposed recently on the basis of spectroscopy and theory to be the active oxidant in Cu-doped zeolite catalysts that perform the same reaction as pMMO [336,337]. Many studies of synthetic dicopper-oxygen intermediates have aimed to address the aforementioned issues (as well as others), and these have been summarized in extensive reviews, to which readers interested in work appearing prior to early 2012 are pointed [261][262][263][264][265][266][338][339][340][341].…”

Section: Dicopper Models Of Dicopper Active Sites In Enzymesmentioning

confidence: 99%

Transition Metal Complexes and the Activation of Dioxygen

Yee

Tolman

2014

Metal Ions in Life Sciences

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In order to address how diverse metalloprotein active sites, in particular those containing iron and copper, guide O₂binding and activation processes to perform diverse functions, studies of synthetic models of the active sites have been performed. These studies have led to deep, fundamental chemical insights into how O₂coordinates to mono- and multinuclear Fe and Cu centers and is reduced to superoxo, peroxo, hydroperoxo, and, after O-O bond scission, oxo species relevant to proposed intermediates in catalysis. Recent advances in understanding the various factors that influence the course of O₂activation by Fe and Cu complexes are surveyed, with an emphasis on evaluating the structure, bonding, and reactivity of intermediates involved. The discussion is guided by an overarching mechanistic paradigm, with differences in detail due to the involvement of disparate metal ions, nuclearities, geometries, and supporting ligands providing a rich tapestry of reaction pathways by which O₂is activated at Fe and Cu sites.

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Coordination chemistry and reactivity of copper in zeolites

Cited by 167 publications

References 121 publications

Effect of the Nature and Location of Copper Species on the Catalytic Nitric Oxide Selective Catalytic Reduction Performance of the Copper/SSZ‐13 Zeolite

Effect of the Nature and Location of Copper Species on the Catalytic Nitric Oxide Selective Catalytic Reduction Performance of the Copper/SSZ‐13 Zeolite

Catalytic properties of extraframework iron-containing species in ZSM-5 for N2O decomposition

Transition Metal Complexes and the Activation of Dioxygen

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