Rationales for the selection of the best precursor for potassium doping of cobalt spinel based deN2O catalyst

Maniak, Gabriela; Stelmachowski, Paweł; Kotarba, Andrzej; Sojka, Zbigniew; Rico-Pérez, Verónica; Bueno‐López, Agustín

doi:10.1016/j.apcatb.2013.01.068

Cited by 83 publications

(68 citation statements)

References 27 publications

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“…It also stimulates recombination of surface oxygen intermediates, closing the catalytic cycle [11,12]. The positive role of the alkali promoters in enhancement of the Co 3 O 4 activity increases in the order: Na \ K \ Cs, and exhibits a strongly non-monotonous character as a function of surface coverage [11,12,16]. Among them, potassium and cesium are the most often investigated due to their strongest promotional effects.…”

Section: Introductionmentioning

confidence: 99%

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Optimization of cesium and potassium promoter loading in alkali-doped Zn0.4Co2.6O4|Al2O3 catalysts for N2O abatement

Ciura

Grzybek

Wojcik

et al. 2017

Reac Kinet Mech Cat

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A series of potassium or cesium doped Zn 0.4 Co 2.6 O 4 |Al 2 O 3 catalysts with different alkali loadings were prepared, characterized with respect to chemical composition (XRF), structure (XRD, RS) morphology (TEM), and the alkali promoter thermal stability. A strong beneficial effect on the deN 2 O activity of the Zn 0.4 Co 2.6 O 4 |Al 2 O 3 catalyst (decrease in the T 50% by about 80°C) was observed for both promoters at different surface coverages. It was found that in comparison to a rather narrow range of optimal cesium loading (0.5-2 atoms/nm 2 ) a comparable promotional effect of potassium doping was observed for a slightly wider surface concentrations (0.5-3 atoms/nm 2 ). Such difference was attributed to surface dispersion of potassium over the alumina support and the spinel active phase, while cesium was found to be located mainly on the spinel phase. For practical applications, the superiority of potassium over cesium consist in fact that a similar beneficial effect is associated with much higher thermal stability in the temperature range of the catalyst deN 2 O operation and lower price of the promoter precursor.

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Section: Introductionmentioning

confidence: 99%

“…In the particular case of potassium, it has been found that the promotional effect strongly depends on the precursor nature (K 2 CO 3 , KNO 3 , CH 3 COOK, KOH), and the highest activity was observed for K 2 CO 3 . It has been assigned to the best surface dispersion and thermal stability of the potassium promoter [16].…”

Section: Introductionmentioning

confidence: 99%

Optimization of cesium and potassium promoter loading in alkali-doped Zn0.4Co2.6O4|Al2O3 catalysts for N2O abatement

Ciura

Grzybek

Wojcik

et al. 2017

Reac Kinet Mech Cat

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“…One of the simple promising generic systems exhibiting high catalytic activity in this reaction is cobalt spinel [16,17,18,19,20], which can be additionally modified by structural [21,22,23,24] and surface donation [24,25,26,27,28] …”

Section: Introductionmentioning

confidence: 99%

Strong dispersion effect of cobalt spinel active phase spread over ceria for catalytic N2O decomposition: The role of the interface periphery

Grzybek

Stelmachowski

Gudyka

et al. 2016

Applied Catalysis B: Environmental

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dispersion effect of cobalt spinel active phase spread over ceria for catalytic N2O decomposition: the role of the interface periphery, Applied Catalysis B, Environmental http://dx.doi.org/10. 1016/j.apcatb.2015.07.027 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The catalytic tests in deN 2 O reaction revealed that the 10 wt.% of cobalt spinel in supported system is able to reproduce the activity of bare Co 3 O 4 catalyst. However, it was found that the catalyst with the lowest content of Co 3 O 4 equal to 1 wt.% exhibits the highest apparent reaction rate per mass of the spinel active phase. The observed activity was explained basing on the transmission electron microscopy analysis in terms of the dispersion of spinel phase over ceria support. A simple model that accounts for the observed strong dispersion effect is proposed. It consists in a two-step mechanism, where N 2 O is dissociated on the spinel nanograins and the resultant oxygen species are preferentially recombined at the Co 3 O 4 /CeO 2 interface periphery.

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“…The reported N 2 O decomposition mechanism on various metal oxide catalysts involves the following steps: (i) N 2 O adsorption via electron donation from the catalyst surface to the adsorbate; (ii) N-O bond destabilization, which leads to its scission and the liberation of N 2 molecule and the formation of an adsorbed O´species; and (iii) recombination of two O´species and desorption of one oxygen molecule. Thus, this reaction requires the coexistence of a redox couple on the catalysts surfaces, such as Co 2+ -Co 3+ [7][8][9][10][11][12][13][14][15][16]43], Cu + -Cu ++ [21,22], Ni 0 -Ni 2+ [23,24]. In this respect, our XPS analysis (Figure 7) revealed the presence of Ni 0 -Ni 2+ redox couple on the surfaces of bare NiO and Gd-promoted NiO.…”

Section: Catalytic Activity Measurementsmentioning

confidence: 83%

Rare Earth-Promoted Nickel Oxide Nanoparticles as Catalysts for N2O Direct Decomposition

et al. 2016

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Abstract:For this paper, a series of rare earth (Gd, La, Sm) promoted NiO catalysts were prepared by using the microwave-assisted precipitation method and tested for N 2 O direct decomposition. The obtained solids have been characterized by using various techniques. X-ray diffraction (XRD) results revealed that the incorporation of RE oxides into NiO significantly decreases its crystallite size. Field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations indicated that the addition of RE oxides swells the NiO particles yielding particles into a rice-like morphology. N 2 adsorption studies showed a sharp surface area increase as well as mesoporosity development accompanied the RE incorporation. It was found that the RE oxides significantly enhance the NiO activity.

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Rationales for the selection of the best precursor for potassium doping of cobalt spinel based deN2O catalyst

Cited by 83 publications

References 27 publications

Optimization of cesium and potassium promoter loading in alkali-doped Zn0.4Co2.6O4|Al2O3 catalysts for N2O abatement

Optimization of cesium and potassium promoter loading in alkali-doped Zn0.4Co2.6O4|Al2O3 catalysts for N2O abatement

Strong dispersion effect of cobalt spinel active phase spread over ceria for catalytic N2O decomposition: The role of the interface periphery

Rare Earth-Promoted Nickel Oxide Nanoparticles as Catalysts for N2O Direct Decomposition

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