Modeling of NOx adsorption–desorption–reduction cycles on a ruthenium loaded Na–Y zeolite

Labaki, Madona; Issa, May; Smeekens, Sylvia; Heylen, Steven; Kirschhock, Christine; Villani, Kenneth; Jeguirim, Mejdi; Habermacher, David; Brilhac, Jean-François; Martens, Johan A.

doi:10.1016/j.apcatb.2010.03.002

Cited by 9 publications

(5 citation statements)

References 33 publications

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“…Even though only NO2 is supplied to the system, other nitrogen oxides-containing species (as NO) are formed due to reduction of NO2 in the presence of activated carbon [11][12][13][14][15][16][17]. The reduction of NO2 to NO is highly undesirable because the separation capacities of activated carbons for NO are negligible.…”

Section: Nox Adsorption On the Different Activated Carbonsmentioning

confidence: 99%

“…Despite the emission reduction measures implemented for automotive and industrial exhaust gases [13][14][15][16], vehicle occupants and urban population are particularly affected by high or even increasing nitrogen oxides immissions. As a result, the interest in adsorptive cabin air filters and HVAC (Heating, Ventilation and Air Conditioning) filters is rising.…”

Section: Introductionmentioning

confidence: 99%

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The Potential of Activated Carbon Made of Agro-Industrial Residues in NOx Immissions Abatement

et al. 2017

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Abstract:The treatment of NO x from automotive gas exhaust has been widely studied, however the presence of low concentrations of NO x in confined areas is still under investigation. As an example, the concentration of NO 2 can approximate 0.15 ppmv inside vehicles when people are driving on highways. This interior pollution becomes an environmental problem and a health problem. In the present work, the abatement of NO 2 immission is studied at room temperature. Three activated carbons (ACs) prepared by physical (CO 2 or H 2 O) or chemical activation (H 3 PO 4 ) are tested as adsorbents. The novelty of this work consists in studying the adsorption of NO 2 at low concentrations that approach real life immission concentrations and is experimentally realizable. The ACs present different structural and textural properties as well as functional surface groups, which induce different affinities with NO 2 . The AC prepared using water vapor activation presents the best adsorption capacity, which may originate from a more basic surface. The presence of a mesoporosity may also influence the diffusion of NO 2 inside the carbon matrix. The high reduction activity of the AC prepared from H 3 PO 4 activation is explained by the important concentration of acidic groups on its surface.

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Section: Nox Adsorption On the Different Activated Carbonsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Potential of Activated Carbon Made of Agro-Industrial Residues in NOx Immissions Abatement

et al. 2017

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“…To remedy the persistent formation of nitrate, we modified the material by introduction of ruthenium as yet a further cation in the framework. Previously, it was observed that the presence of Ru in Na–Y zeolite adsorbent led to a fast, reversible adsorption mechanism for NO x . , During adsorption–desorption cycles, Ru inside the zeolite cavities reversibly changed oxidation state and position, generating and destroying the sodium-water networks in the pores which served as N 2 O 3 adsorption site. Small amounts of metallic Ru on the outside of the zeolite crystals furthermore served as efficient oxidation catalyst converting part of the NO into NO 2 .…”

Section: Resultsmentioning

confidence: 99%

“…X-ray diffraction before and after pelletizing indicated no structural change of the zeolite. Adsorption evaluation was done on a dual-line unit with the adsorbent bed held in a quartz tube as described elsewhere. , The following standard procedure was applied if not stated differently: the zeolite was heated to 300 °C under a flow of nitrogen containing 5% O 2 and 3% H 2 O before NO x adsorption–desorption cycles were started. Typically the adsorption phase was composed of 1000–1500 ppm NO x , 5% O 2 , 3% H 2 O, and balance N 2 .…”

Section: Methodsmentioning

confidence: 99%

NO_x Adsorption Site Engineering in Ru/Ba,Na–Y Zeolite

et al. 2011

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Modern concepts of NO x elimination from lean-burn exhaust gases are based on barium compounds trapping NO x as nitrates. 1À4 NO x temporarily stored under lean burn conditions is desorbed and reduced to N 2 using a spike of rich gas produced by the engine. The forthcoming EURO 6 legislation imposes very stringent limits on NO x emissions and is triggering a renewed interest in NO x traps. Zeolites containing alkali or alkaline earth cations offer great potential in NO x elimination systems. 5À7 The combination of BaÀY zeolite with nonthermal plasma has been shown to perform well in selective catalytic NO x reduction with hydrocarbons. 8À15] In the temperature window 100À177 °C BaÀY zeolite forms large amounts of nitrate, but decomposition of these nitrates is problematic. 16 However, the functionality of zeolites, porous crystalline aluminosilicates with well-defined cavities and channels, greatly is determined by the positions of the cations balancing the framework charge. Therefore, an optimization of the decoration of the cages of zeolite Y with a specific composition of cations was expected to remedy or even remove the problem of nitrate formation. The here investigated zeolite Y is of faujasite topology (FAU) with a typical framework composition of Na 52 Al 52 Si 140 O 384 (Figure 1). In general, aluminosilicate zeolites consist of corner sharing oxygen tetrahedra with central Si or Al atoms. The FAU topology can be thought of being assembled from edgewise connected double six rings (D6Rs) (Figure .1). This results in a large and a small cavity system being composed of large supercages (sc) and of sodalite cages (sod), connected via their 12-rings and 6-rings, respectively. Because of the high symmetry of the framework, cations which balance the negative charge caused by the presence of aluminum, mostly occupy well-defined positions.Depending on the nature and charge of the cations different sites are preferred. 17 A more detailed description of cation sites in FAU can be found in the Supporting Information. ' EXPERIMENTAL SECTIONZeolite NaÀY (Si/Al atomic ratio of 2.7, Na 52 Al 52 Si 140 O 384 Zeocat) was cation exchanged with an aqueous solution of BaCl 2 .2H 2 O (g99+%, Acros) as described in Monticelli et al.. [16] After filtration and washing with deionized water, the Ba,NaÀY zeolite was dried in static air at 60 °C. Elemental analysis on this Ba,NaÀY zeolite was performed by ICP-AES (analyzed at Bodemkundige Dienst van Belgi€ e). The unit cell composition corresponded to Ba 17.3 Na 17.3 Al 52 Si 140 O 384 . An increased Ba content was achieved by a second ion-exchange after calcination at 500 °C for 4 h. Elemental analysis resulted in a unit cell composition of Ba 23.5 Na 5.0 Al 52 Si 140 O 384 . Ba,NaÀY zeolite was further loaded with ruthenium by suspending 1 g of zeolite powder in 100 mL aqueous solution of RuCl 3 (99+%, anhydrous, Acros), and stirring at ambient temperature for 2.5 h. During the loading process, the initial pH was set at 8.5 by addition of ammonia to avoid ruthenium precipita...

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“…NO x are also applied in various secondary processes, generating harmful molecules as ozone and acid compounds. Several processes were used for NO x emissions treatment, including NO x storage and reduction (NSR) and selective catalytic reduction (SCR) [ 1 , 2 , 3 , 4 ]. These methods are particularly suitable for the treatment of automotive exhaust gases, but they are expensive and result in technically complicated applications in industrial plants.…”

Section: Introductionmentioning

confidence: 99%

Factors Influencing NO2 Adsorption/Reduction on Microporous Activated Carbon: Porosity vs. Surface Chemistry

et al. 2018

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The textural properties and surface chemistry of different activated carbons, prepared by the chemical activation of olive stones, have been investigated in order to gain insight on the NO2 adsorption mechanism. The parent chemical activated carbon was prepared by the impregnation of olive stones in phosphoric acid followed by thermal carbonization. Then, the textural properties and surface chemistry were modified by chemical treatments including nitric acid, sodium hydroxide and/or a thermal treatment at 900 °C. The main properties of the parent and modified activated carbons were analyzed by N2-adsorption, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) techniques, in order to enlighten the modifications issued from the chemical and thermal treatments. The NO2 adsorption capacities of the different activated carbons were measured in fixed bed experiments under 500 ppmv NO2 concentrations at room temperature. Temperature programmed desorption (TPD) was applied after adsorption tests in order to quantify the amount of the physisorbed and chemisorbed NO2. The obtained results showed that the development of microporosity, the presence of oxygen-free sites, and the presence of basic surface groups are key factors for the efficient adsorption of NO2.

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Modeling of NOx adsorption–desorption–reduction cycles on a ruthenium loaded Na–Y zeolite

Cited by 9 publications

References 33 publications

The Potential of Activated Carbon Made of Agro-Industrial Residues in NOx Immissions Abatement

The Potential of Activated Carbon Made of Agro-Industrial Residues in NOx Immissions Abatement

NO_x Adsorption Site Engineering in Ru/Ba,Na–Y Zeolite

Factors Influencing NO2 Adsorption/Reduction on Microporous Activated Carbon: Porosity vs. Surface Chemistry

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Modeling of NOx adsorption–desorption–reduction cycles on a ruthenium loaded Na–Y zeolite

Cited by 9 publications

References 33 publications

The Potential of Activated Carbon Made of Agro-Industrial Residues in NOx Immissions Abatement

The Potential of Activated Carbon Made of Agro-Industrial Residues in NOx Immissions Abatement

NOx Adsorption Site Engineering in Ru/Ba,Na–Y Zeolite

Factors Influencing NO2 Adsorption/Reduction on Microporous Activated Carbon: Porosity vs. Surface Chemistry

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NO_x Adsorption Site Engineering in Ru/Ba,Na–Y Zeolite