Alkali metals as promoters in Co–Mn–Al mixed oxide for N2O decomposition

Obalová, Lucie; Karásková, Kateřina; Wach, Anna; Kuśtrowski, Piotr; Mamulová-Kutláková, K.; Michalik, Svatopluk; Jirátová, Květa

doi:10.1016/j.apcata.2013.05.011

Cited by 66 publications

(62 citation statements)

References 49 publications

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“…Among a large number of catalysts tested for the decomposition of N 2 O, cobalt spinels presented excellent catalytic activities which makes them promising for practical application in abatement of N 2 O emitted in waste gases from HNO 3 production plants [3][4][5]. To the best of our knowledge, only two research groups reported on manufacturing of shaped cobalt spinel based catalysts in pilot plant scale conditions [6][7][8]. In both cases, the conventional packed beds with pelletized cobalt spinel based catalysts were used for N 2 O decomposition.…”

Section: Introductionmentioning

confidence: 97%

Advantage of the single pellet string reactor for testing real-size industrial pellets of potassium-doped CoMnAl catalyst for the decomposition of N2O

Klyushina

Pacultová

Obalová

2015

Reac Kinet Mech Cat

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Two tubular laboratory reactors, the single pellet string reactor (i.d. = 0.55 cm) and the fixed bed reactor (i.d. = 5 cm) were compared on the basis of laboratory experiments of N 2 O catalytic decomposition and measurements of residence time distribution curves. K/Co 4 MnAlO x mixed oxide in the form of cylinders (5.1 mm 9 5.1 mm) was used as a catalyst. The influence of external diffusion, deviation from plug flow and influence of axial dispersion on N 2 O conversion obtained in both reactors were discussed. The influence of macroscopic phenomena on the rate of catalytic reaction was significantly lower in the single pellet string reactor, which predetermined it as a suitable laboratory reactor for testing of real-size industrial catalysts. Experimentally obtained results were confirmed by mathematical modeling.Keywords Single pellet string reactor Á Fixed bed reactor Á External diffusion Á Axial dispersion Á Peclet number Á RTD List of symbolsKnudsen diffusivity (m 2 s -1 ) D ij Binary diffusion coefficient of molecular diffusivity (m 2 s -1 )

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Section: Introductionmentioning

confidence: 97%

Advantage of the single pellet string reactor for testing real-size industrial pellets of potassium-doped CoMnAl catalyst for the decomposition of N2O

Klyushina

Pacultová

Obalová

2015

Reac Kinet Mech Cat

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“…According to reported studies [2,20,[22][23][24], mechanism of the N 2 O catalytic decomposition can be described as a charge donation from the catalyst to the anti-bonding orbital of N 2 O, which destabilizes the N-O bond, leading to scission. Therefore, electron charge transfer from the metal ion to the N 2 O molecule is a crucial step for N 2 O catalytic decomposition [24].…”

Section: N 2 O Catalytic Decompositionmentioning

confidence: 97%

“…Therefore, electron charge transfer from the metal ion to the N 2 O molecule is a crucial step for N 2 O catalytic decomposition [24]. The reduction of the metal ion to a low oxidation state is a subsequent, very important step for the regeneration of the active centers [20].…”

Section: N 2 O Catalytic Decompositionmentioning

confidence: 99%

“…The N 2 O catalytic decomposition over alkali promoted Co-Mn-Al mixed oxides proceeds via a cationic redox mechanism when transition metal ions act as donor centers of surface electrons, stimulating the transfer of electron density for activation of the N 2 O molecule, and further as electron acceptor centers for the resultant surface O -intermediates [20]. According to reported studies [2,20,[22][23][24], mechanism of the N 2 O catalytic decomposition can be described as a charge donation from the catalyst to the anti-bonding orbital of N 2 O, which destabilizes the N-O bond, leading to scission.…”

Section: N 2 O Catalytic Decompositionmentioning

confidence: 99%

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Optimization of Cs content in Co–Mn–Al mixed oxide as catalyst for N2O decomposition

et al. 2015

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A series of Co-Mn-Al mixed oxide catalysts with different Cs contents (0.5-4.6 wt%) was prepared by calcination of Co-Mn-Al hydrotalcite (Co:Mn:Al = 4:1:1), followed by impregnation by cesium salt (CsNO 3 , Cs 2 CO 3 ) using the pore filling method. Chemical analysis, N 2 sorption, temperature programmed reduction (TPR)-H 2 , temperature programmed desorption (TPD)-CO 2 and TPD-NH 3 and X-ray photoelectron spectroscopy (XPS) were used to characterize the catalysts. All prepared catalysts were tested for N 2 O catalytic decomposition in inert gas and in the presence of oxygen, water vapor and nitric oxide. The influence of Cs salts used for catalyst preparation and cesium content on catalyst activity were studied. A significant increase in catalytic activity with increasing amount of cesium promoter was observed without respect to the Cs precursor. The strong promotional effect of cesium is electronic in nature and is discussed in term of changes in surface composition and catalyst reducibility.

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“…As pesquisas têm focado no desenvolvimento de catalisadores para essa reação, entre eles: metais nobres [5,6], óxidos de metais de transição [7][8][9] e íons trocados em zeólitas [10][11][12]. Os metais nobres, como Rh e Ru, apresentam altas conversões na decomposição de N 2 O (de-N 2 O), em baixas temperaturas.…”

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Estudo do desempenho catalítico das zeólitas Beta e ZSM-5 contendo ferro para decomposição de óxido nitroso

Moura

Batista

2017

Matéria (Rio J.)

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RESUMOCatalisadores Fe-ZSM-5 tem mostrado alta atividade para decomposição de N 2 O (de-N 2 O), mas poucos trabalhos apresentam o seu desempenho junto com gases que coexistem nas emissões (CO 2 Palavras-chave: óxido nitroso, catalisador, Fe-ZSM-5, Fe-BETA. ABSTRACTFe-ZSM-5 catalysts has shown high activity for decomposition of N 2 O (de-N 2 O), but few works show their performance with coexisting gas emissions (CO 2 , CH 4 , O 2 and H 2 O). Recently, Fe-BETA presented N 2 O conversion more high than Fe-ZSM-5, however, the activity of these catalysts still needs to compare in real conditions. This work aims to study the performance of Fe-BETA, Fe-ZSM-5 and Fe 2 O 3 in the de-N 2 O with addition of gases present in real conditions. For this, Fe-BETA (prepared by ion exchange), Fe-ZSM-5 and Fe 2 O 3 catalysts were calcined, characterized by XRF, XRD and H 2 -TPR and, evaluated in the N 2 O decomposition in the presence of CO 2 , CH 4 , O 2 and H 2 O. The results showed the presence of iron oxide on surface and iron ions compensating load in the structure of the zeolites. The N 2 O conversion increased with increasing reaction temperature and the Fe-ZSM-5 and Fe-BETA catalysts were much more active than Fe 2 O 3 pure. These results show that the iron species in the exchange position of zeolites are the most active for the reaction of N 2 O decomposition. The Fe-ZSM-5 and Fe-BETA catalysts showed high activity (> 90%) and resistance in the presence of CO 2 , CH 4 , O 2 and H 2 O. Fe-BETA was more selective the reaction of decomposition of N 2 O and showed great potential for the reduction of N 2 O emissions in real conditions.

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Alkali metals as promoters in Co–Mn–Al mixed oxide for N2O decomposition

Cited by 66 publications

References 49 publications

Advantage of the single pellet string reactor for testing real-size industrial pellets of potassium-doped CoMnAl catalyst for the decomposition of N2O

Advantage of the single pellet string reactor for testing real-size industrial pellets of potassium-doped CoMnAl catalyst for the decomposition of N2O

Optimization of Cs content in Co–Mn–Al mixed oxide as catalyst for N2O decomposition

Estudo do desempenho catalítico das zeólitas Beta e ZSM-5 contendo ferro para decomposição de óxido nitroso

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