scholarly journals NOx Removal by Selective Catalytic Reduction with Ammonia over a Hydrotalcite-Derived NiFe Mixed Oxide

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 384 ◽  
Author(s):  
Ruonan Wang ◽  
Xu Wu ◽  
Chunlei Zou ◽  
Xiaojian Li ◽  
Yali Du
Keyword(s):  
Selective Catalytic Reduction ◽  
Calcination Temperature ◽  
Mixed Oxide ◽  
Catalytic Reduction ◽  
Catalytic Performance ◽  
Mixed Oxide Catalysts ◽  
Nh3 Scr ◽  
Redox Capacity ◽  
So2 Resistance ◽  
Catalytic Stability

A series of NiFe mixed oxide catalysts were prepared via calcining hydrotalcite-like precursors for the selective catalytic reduction of nitrogen oxides (NOx) with NH3 (NH3-SCR). Multiple characterizations revealed that catalytic performance was highly dependent on the phase composition, which was vulnerable to the calcination temperature. The MOx phase (M = Ni or Fe) formed at a lower calcination temperature would induce more favorable contents of Fe2+ and Ni3+ and as a result contribute to the better redox capacity and low-temperature activity. In comparison, NiFe2O4 phase emerged at a higher calcination temperature, which was expected to generate more Fe species on the surface and lead to a stable structure, better high-temperature activity, preferable SO2 resistance, and catalytic stability. The optimum NiFe-500 catalyst incorporated the above virtues and afforded excellent denitration (DeNOx) activity (over 85% NOx conversion with nearly 98% N2 selectivity in the region of 210–360 °C), superior SO2 resistance, and catalytic stability.

scholarly journals The synthesis of CuyMnzAl1−zOx mixed oxide as a low-temperature NH3-SCR catalyst with enhanced catalytic performance

2018 ◽  
Vol 47 (9) ◽  
pp. 2992-3004 ◽  
Author(s):  
Qinghua Yan ◽  
Sining Chen ◽  
Lei Qiu ◽  
Yanshan Gao ◽  
Dermot O'Hare ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Layered Double Hydroxides ◽  
Mixed Oxide ◽  
Catalytic Reduction ◽  
Catalytic Performance ◽  
Scr Catalyst ◽  
Nh3 Scr ◽  
New Type ◽  
Double Hydroxides

A new type of low-temperature selective catalytic reduction (SCR) catalyst, CuyMnzAl1−zOx, derived from layered double hydroxides is presented in this contribution.

scholarly journals Novel Preparation of Cu and Fe Zirconia Supported Catalysts for Selective Catalytic Reduction of NO with NH3

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 55
Author(s):  
Katarzyna Świrk ◽  
Ye Wang ◽  
Changwei Hu ◽  
Li Li ◽  
Patrick Da Costa ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Experimental Conditions ◽  
One Pot ◽  
Nh3 Scr ◽  
Scr Of No ◽  
Temperature Programmed ◽  
Stationary Sources

Copper and iron promoted ZrO2 catalysts were prepared by one-pot synthesis using urea. The studied catalysts were characterized by XRD, N2 physisorption, XPS, temperature-programmed desorption of NH3 (NH3-TPD), and tested by the selective catalytic reduction by ammonia (NH3-SCR) of NO in the absence and presence of water vapor, under the experimental conditions representative of exhaust gases from stationary sources. The influence of SO2 on catalytic performance was also investigated. Among the studied catalysts, the Fe-Zr sample showed the most promising results in NH3-SCR, being active and highly selective to N2. The addition of SO2 markedly improved NO and NH3 conversions during NH3-SCR in the presence of H2O. The improvement in acidic surface properties is believed to be the cause.

Fe and Mn mixed oxide catalysts supported on Sn-modified TiO2 for the selective catalytic reduction of NO with NH3 at low temperature

2022 ◽  
Author(s):  
Zhitao Han ◽  
Huan Du ◽  
Duo Xu ◽  
Yu Gao ◽  
Shaolong Yang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Mixed Oxide ◽  
Catalytic Reduction ◽  
Oxide Catalysts ◽  
Reduction Of No ◽  
Sn Doping ◽  
Mixed Oxide Catalysts ◽  
Fe And Mn ◽  
Low Temperature Scr

FeMn/SnxTiO2 catalysts were synthesized by introducing Sn as an additive to modify TiO2 supports, and the Sn doping could improve the SO2 tolerance and low-temperature SCR activity significantly.

scholarly journals Selective Catalytic Reduction of NO with NH3 over Ce-W-Ti Oxide Catalysts Prepared by Solvent Combustion Method

2018 ◽  
Vol 8 (12) ◽  
pp. 2430 ◽  
Author(s):  
Xinbo Zhu ◽  
Yaolin Wang ◽  
Yu Huang ◽  
Yuxiang Cai
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Space Velocity ◽  
Combustion Method ◽  
Catalytic Performance ◽  
Solution Combustion ◽  
X Ray ◽  
Nh3 Scr ◽  
Scr Of No ◽  
Temperature Programmed

In this work, a series of Ce-W-Ti catalysts were synthesized using a solution combustion method for the selective catalytic reduction (SCR) of NO with NH3 at low temperatures. The reaction performance of NH3-SCR of NO was significantly improved over the Ce-W-Ti catalysts compared to Ce0.4Ti and W0.4Ti catalysts, while Ce0.2W0.2Ti showed the best activity among all the samples. The Ce0.2W0.2Ti catalyst exhibited over 90% removal of NO and 100% N2 selectivity in the temperature range of 250–400 °C at a gas hourly space velocity (GHSV) of 120,000 mL·g−1·h−1. The Ce-W-Ti catalysts were characterized using N2 adsorption-desorption, X-ray diffraction, X-ray photoelectron spectrometry and temperature programmed desorption of NH3 to establish the structure-activity relationships of the Ce-W-Ti catalysts. The excellent catalytic performance of the Ce0.2W0.2Ti catalyst could be associated with the larger specific surface area, highly dispersed Ce and W species, increased amount of surface adsorbed oxygen (Oads) and enhanced total acidity on the catalyst surfaces.

Cr–MnOx mixed-oxide catalysts for selective catalytic reduction of NOx with NH3 at low temperature

2010 ◽  
Vol 276 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Zhihang Chen ◽  
Qing Yang ◽  
Hua Li ◽  
Xuehui Li ◽  
Lefu Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Mixed Oxide ◽  
Catalytic Reduction ◽  
Oxide Catalysts ◽  
Mixed Oxide Catalysts ◽  
Reduction Of Nox

Selective Catalytic Reduction of NOX on Cr-Mn Mixed Oxide at Low Temperature

2011 ◽  
Vol 233-235 ◽  
pp. 1564-1567
Author(s):  
Zhi Hang Chen ◽  
Xue Hui Li ◽  
Chao Ping Cen ◽  
Xiang Gao ◽  
Le Fu Wang
Keyword(s):  
Citric Acid ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Mixed Oxide ◽  
Mixed Oxides ◽  
Catalytic Reduction ◽  
Space Velocity ◽  
Excess Oxygen ◽  
Mixed Oxide Catalysts ◽  
Acid Method

The solid state reaction method, coprecipitation method and citric acid method were employed for the preparation of Cr-Mn mixed-oxide catalysts. Experimental results showed that this catalytic system has good selective catalytic reduction (SCR) properties of NOxby ammonia in the presence of excess oxygen at low temperature (80-220°C). 97.8% conversion of NOxwith 100% selectivity of N2had been achieved on Cr-MnOxmixed oxide prepared by the citric acid method at 120°C with the space velocity of 30,000 h-1. X-ray diffraction, BET were adopted for the characterization of the active phase. The characterization results showed that a new crystal phase CrMn1.5O4generated in mixed oxides which was the active center of the Cr-Mn catalysts.

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