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.

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.

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 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.

Recent advances in copper-based zeolite catalysts with low-temperature activity for the selective catalytic reduction of NOx with hydrocarbons

2020 ◽  
Vol 44 (3) ◽  
pp. 817-831 ◽  
Author(s):  
Junqiang Xu ◽  
Yahua Qin ◽  
Honglin Wang ◽  
Fang Guo ◽  
Jiaqing Xie
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Zeolite Catalysts ◽  
Design Strategies ◽  
Recent Advances ◽  
Reduction Of Nox

This paper highlights the design strategies of the copper-based zeolite catalysts with excellent catalytic activity at low temperature for HC-SCR.

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 Solid Selective Catalytic Reduction: A Promising Approach towards Reduction of NOx Emission from Exhaust of CI Engines

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
M. K. Yadav ◽  
A. K. Srivastava
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Diesel Engines ◽  
Urban Areas ◽  
Catalytic Reduction ◽  
Nox Emission ◽  
Engine Exhaust ◽  
Diesel Engine Exhaust ◽  
Reduction Of Nox ◽  
Ci Engines

The rising rate of pollution in urban areas has become a worldwide concern in recent years. Diesel engines are considered one of the largest contributors to environmental pollution caused by exhaust emissions, and they are responsible for several health problems as well. Diesel engines contain carbon monoxide, carbon dioxide, unburned hydrocarbons, and oxides of nitrogen. The reduction of Nitric oxides (NOx) emission from diesel engine exhaust is currently being researched by automotive manufacturers. After much research, selective catalytic reduction (SCR) technology was discovered to be effective in reducing nitrogen oxide emission from diesel engine exhaust. This paper is an attempt to explore the problems associated with the use of selective catalytic reduction (SCR) and compares selective catalytic reduction (SCR) with the latest technology named solid selective catalytic reduction (SSCR) for efficient reduction of NOx emission from the exhaust of diesel engines. The issue of contamination, malfunctioning, and freezing of diesel exhaust fluid (DEF) at low temperatures are the major problems associated with the application of SCR. It is observed that by controlling the quantity of ammonia slip, SSCR can give better performance in the reduction of NOx emission from the exhaust of diesel engines.

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.

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