Cu-modified cryptomelane oxide as active catalyst for CO oxidation reactions

Hernández, Willinton Y.; Centeno, M.A.; Ivanova, Svetlana; Eloy, Pierre; Gaigneaux, Éric M.; Odriozola, J.A.

doi:10.1016/j.apcatb.2012.04.024

Cited by 103 publications

(73 citation statements)

References 64 publications

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“…For the support OMS-2, the overloping peaks (marked as to MnO. 15,18 These results all confirm the interaction between the catalystic metal copper and the support OMS-2. 17,19a More importantly, the reduction peaks αˊ and βˊ of Cu/OMS-2 became obvious, which probably is caused by the enhanced mobility of oxygen.…”

Section: Resultssupporting

confidence: 62%

“…To explore the surface properties of the catalyst, Cu/OMS-2 was characterized by XPS ( Figure S2, see ESI). 15 The Cu 2p spectrum shows that the binding energies of Cu 2p 1/2 and Cu 2p 3/2 are about 954.0 eV and 934.3 eV, and the shake-up satellite peaks of Cu 2p 1/2 and Cu 2p 3/2 are at 962.1 eV and at 944.7 eV, respectively, which demonstrates that Cu 2+ species are existed on the surface of the catalyst. 15 The Cu 2p spectrum shows that the binding energies of Cu 2p 1/2 and Cu 2p 3/2 are about 954.0 eV and 934.3 eV, and the shake-up satellite peaks of Cu 2p 1/2 and Cu 2p 3/2 are at 962.1 eV and at 944.7 eV, respectively, which demonstrates that Cu 2+ species are existed on the surface of the catalyst.…”

Section: Resultsmentioning

confidence: 91%

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Heterogeneous Cu/OMS-2 as an efficient catalyst for the synthesis of tetrasubstituted 1,4-enediones and 4H-pyrido[1,2-a]-pyrimidin-4-ones

Zhang

Meng

et al. 2015

RSC Adv.

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An efficient Cu/OMS-2-catalyzed oxidative heterogeneous protocol has been developed for the synthesis of tetrasubstituted unsymmetrical 1,4-enediones and 4H-pyrido[1,2-a]-pyrimidin-4-ones from 1,4-enediones and amines or 2-aminopyridines. The present catalytic system employs air as the termial oxidant and tolerates a broad range of substrates using low loading copper (1.3 wt%). The Cu/OMS-2 was characterized by various methods, including XRD, XPS, BET as well as TEM/SEM, and the results of H2-TPR shows that the redox ability of the catlayst was improved by the combination of Cu and OMS-2. Moreover, the catalyst is recyclable.

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Section: Resultssupporting

confidence: 62%

Section: Resultsmentioning

confidence: 91%

Heterogeneous Cu/OMS-2 as an efficient catalyst for the synthesis of tetrasubstituted 1,4-enediones and 4H-pyrido[1,2-a]-pyrimidin-4-ones

Zhang

Meng

et al. 2015

RSC Adv.

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“…The states of oxidation of manganese partly determine what kind and how much mono-or divalent cations can enter the tunnels at the time the manganese minerals form (Gruner, 1943;Hildebrand and Mosier, 1974). Furthermore, silver, cesium, copper, nickel, lithium, cobalt, chromium-modified cryptomelane are reported to be synthesized successfully (Santos et al, 2009;Hernández et al, 2012;Özacar et al, 2013;Sun et al, 2014). These cations partially occupy locations within the tunnels to stabilize charge.…”

Section: Discussionmentioning

confidence: 99%

The mineralogical characterization of argentian cryptomelane from Xiangguang Mn–Ag deposit, North China

Fan

Wang

Xing-tao

et al. 2015

Journal of Mineralogical and Petrological Sciences

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Argentian cryptomelane as a quite rare variety is determined during the investigation of Mn-Ag ore samples from Xiangguang deposit along the northern margin of North China craton. The mineral observed by a polarizing petrographic microscope involves concentric ring-band, pisolitic and veinlet structures and greyish white color. The scanning electron microscopy reveals a large number of elongated nanocrystals in the forms of nanofibers and nanorods in this densely natural argentian cryptomelane. The specifically chemical features in two samples of XG-C-1 and XG-C-2 of cryptomelane are: (1) The silver content ranges from about 0.22-3.15 wt%, which is much higher than that of other manganese oxides including ranciéite, chalcophanite and coronodite found in this deposit as well. Both of two argentian cryptomelane samples feature two main Raman scattering contributions at about 580 cm −1 and 630 cm −1 , belonging to the Mn-O lattice vibrations within the MnO 6 octahedral double chains, which can distinguish from other three manganese oxides. The Ag + prefers to locate in the tunnel sites substituting K + of cryptomelane due to its large radius and the same monovalent state with K + . Some chain-width disorders characterized by transmission electron microscopy are probably caused by these cation substitutions.

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“…More over, shoulder peak at 150 • C is observed, implying the presence of active surface oxygen species. The results can be ascribed to the fact that the formation of Cu-O-Mn enhances the activity of surface lattice oxygen (O lat ) [34][35][36]. The loading of Fe 3 O 4 reduces the reducibility of catalyst, probably due to the fact that Fe 3 O 4 nanoparticles partially block the access between H 2 and catalyst surface.…”

Section: Characterizationmentioning

confidence: 90%