scholarly journals Cu- and Fe-speciation in a composite zeolite catalyst for selective catalytic reduction of NOx: insights from operando XAS

2021 ◽  
Author(s):  
Ilia A. Pankin ◽  
Houeida Issa Hamoud ◽  
Kirill A. Lomachenko ◽  
Søren Birk Rasmussen ◽  
Andrea Martini ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Absorption Spectroscopy ◽  
Zeolite Catalyst ◽  
Catalytic Reduction ◽  
Mechanical Mixture ◽  
X Ray ◽  
Fe Speciation ◽  
Reduction Of Nox ◽  
Operando Xas ◽  
X Ray Absorption

Cu-SAPO-34 (Cu-CZC) and Fe-mordenite (Fe-MOR) and their mechanical mixture (50 : 50) have been exhaustively investigated by means of operando X-ray absorption spectroscopy under NH3-SCR conditions.

Insights into sulfur poisoning and regeneration of Cu-SSZ-13 catalysts: In situ Cu and S K-edge XAS studies

2021 ◽  
Author(s):  
Vitaly Mesilov ◽  
Sandra Dahlin ◽  
Susanna Liljegren Bergman ◽  
Peter Sams Hammershøi ◽  
Shibo Xi ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Oxidation State ◽  
Absorption Spectroscopy ◽  
Catalytic Reduction ◽  
Sulfur Poisoning ◽  
X Ray ◽  
Scr Catalysts ◽  
X Ray Absorption

In situ Cu and S K-edge X-ray absorption spectroscopy (XAS) was used for the investigation of sulfur-poisoned and regenerated Cu-SSZ-13 selective catalytic reduction (SCR) catalysts. Sulfur in the oxidation state...

An X-ray absorption study on copper-containing AlPO4-5 for selective catalytic reduction of NOX by propene

2001 ◽  
Vol 11 (5) ◽  
pp. 1441-1446 ◽  
Author(s):  
Ian D. Burton ◽  
Justin S. J. Hargreaves ◽  
David G. Nicholson ◽  
Merete H. Nilsen ◽  
Michael Stockenhuber
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Absorption Study ◽  
X Ray ◽  
Reduction Of Nox ◽  
X Ray Absorption

TNU-9, a new zeolite for the selective catalytic reduction of NO: An in situ X-ray absorption spectroscopy study

2012 ◽  
Vol 295 ◽  
pp. 22-30 ◽  
Author(s):  
Cristina Franch-Martí ◽  
Cristina Alonso-Escobar ◽  
Jose L. Jorda ◽  
Inma Peral ◽  
Juan Hernández-Fenollosa ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Absorption Spectroscopy ◽  
Catalytic Reduction ◽  
Spectroscopy Study ◽  
Reduction Of No ◽  
X Ray ◽  
X Ray Absorption

Integrated operando X-ray absorption and DFT characterization of Cu–SSZ-13 exchange sites during the selective catalytic reduction of NOx with NH3

2012 ◽  
Vol 184 (1) ◽  
pp. 129-144 ◽  
Author(s):  
J.-S. McEwen ◽  
T. Anggara ◽  
W.F. Schneider ◽  
V.F. Kispersky ◽  
J.T. Miller ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
X Ray ◽  
Reduction Of Nox ◽  
X Ray Absorption

scholarly journals In operando XAS investigation of reduction and oxidation processes in cobalt and iron mixed spinels during the chemical loop reforming of ethanol

2017 ◽  
Vol 5 (39) ◽  
pp. 20808-20817 ◽  
Author(s):  
F. Carraro ◽  
O. Vozniuk ◽  
L. Calvillo ◽  
L. Nodari ◽  
C. La Fontaine ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Oxygen Carriers ◽  
X Ray ◽  
Oxidation Processes ◽  
Reduction And Oxidation ◽  
In Operando ◽  
Operando Xas ◽  
X Ray Absorption

FeCo2O4 and CoFe2O4 nanoparticles have been studied as oxygen carriers for the chemical loop reforming of ethanol by using in operando X-ray absorption spectroscopy.

scholarly journals Iron Speciation in Different Saharan Dust Advections and Effect of the Procedural Blank on the Results From X-ray Absorption Spectroscopy and Selective Leaching Experiments

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 735
Author(s):  
Chiara Petroselli ◽  
Beatrice Moroni ◽  
Stefano Crocchianti ◽  
Roberta Selvaggi ◽  
Francesco Soggia ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Saharan Dust ◽  
Residual Fraction ◽  
Selective Leaching ◽  
Iron Speciation ◽  
X Ray ◽  
Fe Speciation ◽  
Leaching Experiments ◽  
X Ray Absorption

In this work, we applied X-ray Absorption Spectroscopy (XAS) and selective leaching experiments for investigating iron speciation in different dust advections collected on different unwashed quartz fiber filters. XAS analysis evidenced a predominance of Fe(III) in 6-fold coordination for Saharan dust and a trend towards Fe(II) and 4-fold coordination in the order: Saharan dust, mixed Saharan, and non-Saharan aerosol samples. The role of the sampling substrate was evaluated explicitly, including in the analysis a set of blank filters. We were able to pinpoint the possible contribution to the overall XAS spectrum of the residual Fe on quartz as the concentration decrease towards the blank value. In particular, the filter substrate showed a negligible effect on the structural trend mentioned above. Furthermore, selective leaching experiments evidenced a predominance of the residual fraction on Fe speciation and indicated the lowest Fe concentrations for which the blank contribution is <20% are 1 μ g for the first three steps of the procedure (releasing the acid-labile, reducible and oxidizable phases, respectively) and 10 μ g for the last step (dissolving the insoluble residuals).

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

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2534
Author(s):  
Yaping Zhang ◽  
Peng Wu ◽  
Ke Zhuang ◽  
Kai Shen ◽  
Sheng Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Selective Catalytic Reduction ◽  
Volume Fraction ◽  
Catalytic Reduction ◽  
Surface Measurement ◽  
X Ray ◽  
Nox Conversion ◽  
Nh3 Adsorption ◽  
Reduction Of Nox

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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