Activity of an iron Colombian natural zeolite as potential geo-catalyst for NH3-SCR of NOx

Gelves, J. F.; Dorkis, Ludovic; Márquez, María del Carmen Bellido; Álvarez-Murillo, A.; González, Lina María; Villa, Aída Luz

doi:10.1016/j.cattod.2018.01.025

Cited by 24 publications

(19 citation statements)

References 69 publications

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“…After adding NH 3 , several bands at 1660 cm −1 , 1600 cm −1 , 1440 cm −1 and 1220 cm −1 were detected. The band at 1600 cm −1 and 1220 cm −1 was associated with the asymmetric and symmetric deformation vibration of NH 3 adsorbed on Lewis acid sites, while the band at 1660 cm −1 and 1440 cm −1 were due to the asymmetric and symmetric deformation of NH 4 + bound to Brönsted acid sites [26,27]. Compared with the results of Figure 9, it could be found that the intensity of bands due to adsorbed NH 3 was significantly increased after being pretreated by SO 2 and O 2 .…”

Section: Resultsmentioning

confidence: 99%

Effect of SO2 on the Selective Catalytic Reduction of NOx over V2O5-CeO2/TiO2-ZrO2 Catalysts

Zhang

Zhuang

et al. 2019

Materials

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The effect of SO2 on the selective catalytic reduction of NOx by NH3 over V2O5-0.2CeO2/TiO2-ZrO2 catalysts was studied through catalytic activity tests and various characterization methods, like Brunner−Emmet−Teller (BET) surface measurement, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray fluorescence (XRF), hydrogen temperature-programmed desorption (H2-TPR), X-ray photoelectron spectroscopy (XPS) and in situ diffused reflectance infrared Fourier transform spectroscopy (DRIFTS). The results showed that the catalyst exhibited superior SO2 resistance when the volume fraction of SO2 was below 0.02%. As the SO2 concentration further increased, the NOx conversion exhibited some degree of decline but could restore to the original level when stopping feeding SO2. The deactivation of the catalyst caused by water in the flue gas was reversible. However, when 10% H2O was introduced together with 0.06% SO2, the NOx conversion was rapidly reduced and became unrecoverable. Characterizations indicated that the specific surface area of the deactivated catalyst was significantly reduced and the redox ability was weakened, which was highly responsible for the decrease of the catalytic activity. XPS results showed that more Ce3+ was generated in the case of reacting with SO2. In situ DRIFTS results confirmed that the adsorption capacity of SO2 was enhanced obviously in the presence of O2, while the SO2 considerably refrained the adsorption of NH3. The adsorption of NOx was strengthened by SO2 to some extent. In addition, NH3 adsorption was improved after pre-adsorbed by SO2 + O2, indicating that the Ce3+ and more oxygen vacancy were produced.

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Section: Resultsmentioning

confidence: 99%

Effect of SO2 on the Selective Catalytic Reduction of NOx over V2O5-CeO2/TiO2-ZrO2 Catalysts

Zhang

Zhuang

et al. 2019

Materials

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“…The Reaction (6) in turn is an overall reaction and under (in) real conditions proceeds in two elementary steps (Reactions (7) and (8)).…”

Section: Resultsmentioning

confidence: 99%

“…Thus, from the Reactions (6), (7), and (8), it can be concluded that information describing the NO/NO 2 ratio is very important to understand the mechanism of the conversion process. The obtained results showed that carbon oxide conversion was realized not only through the oxidation by the oxygen but also through the conversion of NO 2 to NO.…”

Section: Resultsmentioning

confidence: 99%

“…As it was shown by Gelves et al, the process of gas purification from nitrogen oxides and carbon monoxide can proceed without the catalyst usage, however, the necessary temperature for this process is about 500°C and higher. Thus in order to provide the high conversion efficiency of the above‐mentioned pollutants at lower temperatures the selective catalysts are used .…”

Section: Introductionmentioning

confidence: 99%

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NO_x and CO Abatement by applying catalysts with an active coating made of transition non‐precious (CuO–Cr₂O₃, TiO₂) and precious (Pt) metals

Baltrėnas

Urbanas

2019

Env Prog and Sustain Energy

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In this study, the investigation of simultaneous removal of nitrogen oxides and carbon monoxide from gas emissions produced as a result of propane–butane gas combustion was performed. For this purpose, the special experimental prototype with catalysts of the honeycomb structure with an active layer synthesized by applying a plasma spray coating technique was used. During the present investigation, such active materials as precious metals (Pt) and also economically feasible materials such as copper–chromium oxide (CuO–Cr2O3) and titanium oxide (TiO2) were tested and compared. The mechanism of NOx and CO catalytic removal was described taking into account the NO and NO2 conversion. It was established that the initial CO concentration produced as a result of fuel combustion has a negligible impact on its removal efficiency while the initial CO/NOx ratio has a direct influence on the dependence of NOx removal efficiency on operating temperature. With increasing the CO/NOx ratio not only the NOx reduction efficiency can be increased but also the onset temperature of the catalytic conversion process can be lowered. The obtained results indicated that the efficiency of carbon monoxide and nitrogen oxides conversion with the use of tested transition metal oxides can achieve 95% and 80%, respectively. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13145, 2019

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“…The use of natural zeolites as catalyst has an intrinsic limitation related to phase purity, which cannot be controlled as carefully as for synthetic ones [22][23][24][25]. This also implies that the interpretation of the results can be very complex.…”

Section: Introductionmentioning

confidence: 99%

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

et al. 2019

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Natural purified mordenite from Palmarito de Cauto (ZP) deposit, Cuba, was subjected to a hydrothermal ion exchange process in acid medium with Fe2+ or Fe3+ salts (Fe2+ZP and Fe3+ZP). The set of samples was characterized regarding their textural properties, morphology, and crystallinity, and tested in the NO reduction with CO/C3H6. Infrared spectroscopy coupled with NO as a probe molecule was used to give a qualitative description of the Fe species’ nature and distribution. The exchange process caused an increase in the iron loading of the samples and a redistribution, resulting in more dispersed Fe2+ and Fe3+ species. When contacted with the NO probe, Fe2+ZP showed the highest intensity of nitrosyl bands, assigned to NO adducts on isolated/highly dispersed Fe2+/Fe3+ extra-framework sites and FexOy clusters. This sample is also characterized by the highest NO sorption capacity and activity in NO reduction. Fe3+ZP showed a higher intensity of nitrosonium (NO+) species, without a correlation to NO storage and conversion, pointing to the reactivity of small FexOy aggregates in providing oxygen atoms for the NO to NO+ reaction. The same sites are proposed to be responsible for the higher production of CO2 observed on this sample, and thus to be detrimental to the activity in NO SCR.

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Activity of an iron Colombian natural zeolite as potential geo-catalyst for NH3-SCR of NOx

Cited by 24 publications

References 69 publications

Effect of SO2 on the Selective Catalytic Reduction of NOx over V2O5-CeO2/TiO2-ZrO2 Catalysts

Effect of SO2 on the Selective Catalytic Reduction of NOx over V2O5-CeO2/TiO2-ZrO2 Catalysts

NO_x and CO Abatement by applying catalysts with an active coating made of transition non‐precious (CuO–Cr₂O₃, TiO₂) and precious (Pt) metals

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

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Activity of an iron Colombian natural zeolite as potential geo-catalyst for NH3-SCR of NOx

Cited by 24 publications

References 69 publications

Effect of SO2 on the Selective Catalytic Reduction of NOx over V2O5-CeO2/TiO2-ZrO2 Catalysts

Effect of SO2 on the Selective Catalytic Reduction of NOx over V2O5-CeO2/TiO2-ZrO2 Catalysts

NOx and CO Abatement by applying catalysts with an active coating made of transition non‐precious (CuO–Cr2O3, TiO2) and precious (Pt) metals

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

Contact Info

Product

Resources

About

NO_x and CO Abatement by applying catalysts with an active coating made of transition non‐precious (CuO–Cr₂O₃, TiO₂) and precious (Pt) metals