The impact of light and heavy hydrocarbons on the NH3-SCR activity of commercial Cu- and Fe-zeolite catalysts

Positioning the catalysts in front of the turbocharger has gained interest over recent years due to the earlier onset temperature and positive effect of elevated pressure. However, several challenges must be overcome, like presence of higher pollutant concentrations due to the absence or insufficient diesel oxidation catalyst volume at this location. In this context, our study reports a systematic investigation on the effect of pressure and various hydrocarbons during selective catalytic reduction (SCR) of NOx with NH3 over the zeolite-based catalysts Fe-ZSM-5 and Cu-SSZ-13. Using a high-pressure catalyst test bench, the catalytic activity of both zeolite catalysts was measured in the presence and absence of a variety of hydrocarbons under pressures and temperatures resembling the conditions upstream of the turbocharger. The results obtained showed that the hydrocarbons are incompletely converted over both catalysts, resulting in numerous byproducts. The emission of hydrogen cyanide seems to be particularly problematic. Although the increase in pressure was able to improve the oxidation of hydrocarbons and significantly reduce the formation of HCN, sufficiently low emissions could only be achieved at high temperatures. Regarding the NOx conversion, a boost in activity was obtained by increasing the pressure compared to atmospheric reaction conditions, which compensated the negative effect of hydrocarbons on the SCR activity.

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The impact of urea on the performance of metal exchanged zeolites for the selective catalytic reduction of NOxPart I. Pyrolysis and hydrolysis of urea over zeolite catalysts

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2010.03.027 ◽

2010 ◽

Vol 97 (1-2) ◽

pp. 90-97 ◽

Cited By ~ 68

Author(s):

Maik Eichelbaum ◽

Robert J. Farrauto ◽

Marco J. Castaldi

Keyword(s):

Selective Catalytic Reduction ◽

Catalytic Reduction ◽

Zeolite Catalysts ◽

The Impact ◽

Hydrolysis Of ◽

Hydrolysis Of Urea

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Catalytic deactivation mechanism research over Cu/SAPO-34 catalysts for NH3-SCR (I): The impact of 950 °c hydrothermal aging time

Chemical Engineering Science ◽

10.1016/j.ces.2017.10.032 ◽

2018 ◽

Vol 176 ◽

pp. 285-293 ◽

Cited By ~ 16

Author(s):

Dequan Fan ◽

Jun Wang ◽

Tie Yu ◽

Jianqiang Wang ◽

Xiaoqian Hu ◽

...

Keyword(s):

Aging Time ◽

Hydrothermal Aging ◽

Nh3 Scr ◽

Mechanism Research ◽

The Impact ◽

Catalytic Deactivation ◽

Deactivation Mechanism

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NH3-SCR on Fe zeolite catalysts – From model setup to NH3 dosing

Chemical Engineering Journal ◽

10.1016/j.cej.2009.02.037 ◽

2009 ◽

Vol 154 (1-3) ◽

pp. 333-340 ◽

Cited By ~ 53

Author(s):

A. Schuler ◽

M. Votsmeier ◽

P. Kiwic ◽

J. Gieshoff ◽

W. Hautpmann ◽

...

Keyword(s):

Zeolite Catalysts ◽

Nh3 Scr ◽

Model Setup

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The Influence of Ce or Mn Doping on Cu-Based Catalysts for De-NOx with NH3-SCR

Journal of Chemistry ◽

10.1155/2020/1462801 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Lei Jiang ◽

Yixi Cai ◽

Miaomiao Jin ◽

Zengzan Zhu ◽

Yinhuan Wang

Keyword(s):

Low Temperature ◽

Physicochemical Properties ◽

Topological Structure ◽

Zeolite Catalysts ◽

Incipient Wetness Impregnation ◽

Impregnation Method ◽

Performance Tests ◽

Nh3 Scr ◽

Temperature Window ◽

Different Doses

In this study, the de-NOx performance of Cu-based zeolite catalysts supported on topological structure (SSZ-13, BEA, ZSM-5) and loaded with different doses of copper (from 2 to 6 wt.%) was investigated. The preparation of copper-based catalysts adopted the incipient wetness impregnation method. To analyze the physicochemical properties of the catalysts, advanced techniques like BET, XRD, NH3-TPD, H2-TPR, and DRS UV-Vis were used. The performance tests suggested the 4Cu/SSZ-13 catalyst exhibited higher low-temperature activity and wider temperature window. Furthermore, compared with Mn-Cu/SSZ-13, the Ce-Cu/SSZ-13 catalysts exhibited better de-NOx performance.

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