scholarly journals Synthesis of SSZ-13 Zeolite in the Presence of N,N,N-Dimethylethylcyclohexyl Ammonium for Selective Catalytic Reduction of NOx

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Dang Van Long ◽  
Le Thanh Son ◽  
Pham Dinh Trong
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
The United States ◽  
Structure Directing Agent ◽  
Mobile Sources ◽  
Nox Conversion ◽  
Scr Catalysts ◽  
Small Pore ◽  
Reduction Of Nox ◽  
Scr Of Nox

Abstract: Since NOx emission requirements from stationary and mobile sources are more strictly regulated in the United States, Europe, and other countries; researchers have conducted many studies to improve the performance of selective catalytic reduction (SCR) catalysts to meet more and more stringent emission standards. Herein, we reported the synthesis of small pore zeolite (Cu)-SSZ-13 using N,N,N-dimethylethylcyclohexylammonium as the structure directing agent. The catalytic activity of the fresh and hydrothermal aged copper exchanged supported on SSZ-13 catalyst was investigated in the SCR of NOx using NH3 as a reductant. Cu-SSZ-13 possessing a high SCR performance (NOx conversion reached approximately 100% at 250oC), and high hydrothermal stability in combination with an easy synthesis route is considered to be a potential catalyst for SCR application. Keywords: Zeolite, SSZ-13, synthesis, SCR, NOx.

Recent advances in the preparation of zeolites for the selective catalytic reduction of NOx in diesel engines

2019 ◽  
Vol 4 (6) ◽  
pp. 975-985 ◽  
Author(s):  
Ling Zhang ◽  
Qinming Wu ◽  
Xiangju Meng ◽  
Ulrich Müller ◽  
Mathias Feyen ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Diesel Engines ◽  
Catalytic Reduction ◽  
Pore Sizes ◽  
Recent Advances ◽  
Small Pore ◽  
Reduction Of Nox ◽  
Scr Of Nox

Metal-exchanged zeolites with small pore sizes have attracted much attention in recent years due to their application in the selective catalytic reduction (SCR) of NOx in diesel engines.

Catalysts for the selective catalytic reduction of NOx with NH3 at low temperature

2015 ◽  
Vol 5 (9) ◽  
pp. 4280-4288 ◽  
Author(s):  
Wenpo Shan ◽  
Hua Song
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Scr Catalysts ◽  
Small Pore ◽  
Reduction Of Nox

This review presents recent studies on low-temperature NH3-SCR catalysts, particularly Mn-based oxides, V2O5/AC, and Cu-based small pore zeolites.

scholarly journals A review of Mn-containing oxide catalysts for low temperature selective catalytic reduction of NOx with NH3: reaction mechanism and catalyst deactivation

RSC Advances ◽  
2017 ◽  
Vol 7 (42) ◽  
pp. 26226-26242 ◽  
Author(s):  
Shengen Zhang ◽  
Bolin Zhang ◽  
Bo Liu ◽  
Shuailing Sun
Keyword(s):  
Reaction Mechanism ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalyst Deactivation ◽  
Catalytic Reduction ◽  
Oxide Catalysts ◽  
Scr Catalysts ◽  
Reduction Of Nox

The reactions over Mn-containing selective catalytic reduction (SCR) catalysts.

scholarly journals Investigation of Sulfated Iron-Based Catalysts with Different Sulfate Position for Selective Catalytic Reduction of NOx with NH3

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1035
Author(s):  
Baiyu Fan ◽  
Ziyin Zhang ◽  
Caixia Liu ◽  
Qingling Liu
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalyst Surface ◽  
Catalytic Reduction ◽  
Nh3 Adsorption ◽  
Reduction Of Nox ◽  
Iron Based ◽  
Redox Ability ◽  
Scr Of Nox ◽  
Iron Based Catalysts

The Fe/(SZr) and S(Fe/Zr) sulfated iron-based catalysts, prepared by impregnation methods through changing the loading order of Fe2O3 and SO42− on ZrO2, were investigated on selective catalytic reduction (SCR) of NOx by ammonia. It was studied that the existent forms of Fe2O3 and SO42− on the surface of catalysts were affected by the loading order. The Fe/(SZr) catalyst surface had isolated Fe2O3 and SO42− species and followed both the L-H mechanism and the E-R mechanism, whereas the S(Fe/Zr) catalyst contained SO42− specie and sulfate only and mainly followed the E-R pathway. These factors affected the redox ability and NH3 adsorption, which might be key to the SCR reaction.

scholarly journals Fe-Exchanged Small-Pore Zeolites as Ammonia Selective Catalytic Reduction (NH3-SCR) Catalysts

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1324
Author(s):  
Feng Gao
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Short Review ◽  
Industrial Applications ◽  
Zeolite Catalysts ◽  
Hydrothermal Aging ◽  
Theoretical Approaches ◽  
Fe Species ◽  
Scr Catalysts ◽  
Small Pore

Cu-exchanged small-pore zeolites have been extensively studied in the past decade as state-of-the-art selective catalytic reduction (SCR) catalysts for diesel engine exhaust NOx abatement for the transportation industry. During this time, Fe-exchanged small-pore zeolites, e.g., Fe/SSZ-13, Fe/SAPO-34, Fe/SSZ-39 and high-silica Fe/LTA, have also been investigated but much less extensively. In comparison to their Cu-exchanged counterparts, such Fe/zeolite catalysts display inferior low-temperature activities, but improved stability and high-temperature SCR selectivities. Such characteristics entitle these catalysts to be considered as key components of highly efficient emission control systems to improve the overall catalyst performance. In this short review, recent studies on Fe-exchanged small-pore zeolite SCR catalysts are summarized, including (1) the synthesis of small-pore Fe/zeolites; (2) nature of the SCR active Fe species in these catalysts as determined by experimental and theoretical approaches, including Fe species transformation during hydrothermal aging; (3) SCR reactions and structure-function correlations; and (4) a few aspects on industrial applications.

scholarly journals Structural and kinetic changes to small-pore Cu-zeolites after hydrothermal aging treatments and selective catalytic reduction of NOx with ammonia

2017 ◽  
Vol 2 (2) ◽  
pp. 168-179 ◽  
Author(s):  
Jonatan D. Albarracin-Caballero ◽  
Ishant Khurana ◽  
John R. Di Iorio ◽  
Arthur J. Shih ◽  
Joel E. Schmidt ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Hydrothermal Aging ◽  
Small Pore ◽  
Reduction Of Nox

Cu in aged zeolites changes structure during SCR.

scholarly journals Selective Catalytic Reduction of NOx over V2O5-WO3-TiO2 SCR Catalysts—A Study at Elevated Pressure for Maritime Pre-turbine SCR Configuration

2019 ◽  
Vol 5 (3) ◽  
pp. 263-278 ◽  
Author(s):  
Steen R. Christensen ◽  
Brian B. Hansen ◽  
Kim H. Pedersen ◽  
Joakim R. Thøgersen ◽  
Anker D. Jensen
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Elevated Pressure ◽  
Scr Catalysts ◽  
Reduction Of Nox

scholarly journals Selective Catalytic Reduction of NOx with Ammonia and Hydrocarbon Oxidation Over V2O5–MoO3/TiO2 and V2O5–WO3/TiO2 SCR Catalysts

2018 ◽  
Vol 62 (1-4) ◽  
pp. 129-139 ◽  
Author(s):  
Lei Zheng ◽  
Maria Casapu ◽  
Matthias Stehle ◽  
Olaf Deutschmann ◽  
Jan-Dierk Grunwaldt
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Hydrocarbon Oxidation ◽  
Scr Catalysts ◽  
Reduction Of Nox

scholarly journals Selective catalytic reduction of NOx with NH3: opportunities and challenges of Cu-based small-pore zeolites

2021 ◽  
Author(s):  
Yulong Shan ◽  
Jinpeng Du ◽  
Yan Zhang ◽  
Wenpo Shan ◽  
Xiaoyan Shi ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Hydrothermal Stability ◽  
Catalyst Design ◽  
Scr Catalyst ◽  
Nh3 Scr ◽  
Small Pore ◽  
Fast Scr ◽  
Reduction Of Nox ◽  
Significant Opportunity

Abstract Zeolites, as efficient and stable catalysts, are widely used in the environmental catalysis field. Typically, Cu-SSZ-13 with small-pore structure shows excellent catalytic activity for selective catalytic reduction of NOx with ammonia (NH3-SCR) as well as high hydrothermal stability. This review summarizes major advances in Cu-SSZ-13 applied to the NH3-SCR reaction, including the state of copper species, standard and fast SCR reaction mechanism, hydrothermal deactivation mechanism, poisoning resistance, and synthetic methodology. The review gives a valuable summary of new insights on the matching between SCR catalyst design principles and the characteristics of Cu2+-exchanged zeolitic catalysts, highlighting the significant opportunity presented by zeolite-based catalysts. Principles for designing zeolites with excellent NH3-SCR performance and hydrothermal stability are proposed. On the basis of these principles, more hydrothermally stable Cu-AEI and Cu-LTA zeolites are elaborated as well as other alternative zeolites applied to NH3-SCR. Finally, we call attention to the challenges facing Cu-based small-pore zeolites that still need to be addressed.

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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