Influence of nitrogen surface functionalities on the catalytic activity of activated carbon in low temperature SCR of NO  with NH3

Catalysts of Mn/TiO2 and Mn-Ce /TiO2 prepared by co-precipitation method for low temperature selective catalytic reduction (SCR) of NO with NH3 were investigated in this study. The experimental results showed that co-precipitation method after improvement, the NO conversion of Mn-Ce/TiO2 catalyst increased sharply. Meanwhile, the addition of cerium has significant effects on the catalytic activity. Characterizations of catalysts were carried out by XRD, BET and H2-TPR. The characterized results indicated that co-precipitation method after improvement, in temperature windows 150 to 300 °C, showed higher NOx conversion.

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Performance of C2H4 Reductant in Activated-Carbon- Supported MnOx-based SCR Catalyst at Low Temperatures

Energies ◽

10.3390/en12010123 ◽

2018 ◽

Vol 12 (1) ◽

pp. 123 ◽

Cited By ~ 3

Author(s):

Guangli Liu ◽

Dongtai Han ◽

Jie Cheng ◽

Yongshi Feng ◽

Wenbin Quan ◽

...

Keyword(s):

Catalytic Activity ◽

Activated Carbon ◽

Low Temperature ◽

Active Sites ◽

Catalyst Activity ◽

Scr Catalyst ◽

Scr Catalysts ◽

Two Factors ◽

Low Temperature Scr ◽

Mn Concentration

Hydrocarbons as reductants show promising results for replacing NH3 in SCR technology. Therefore, considerable interest exists for developing low-temperature (<200 °C) and environmentally friendly HC-SCR catalysts. Hence, C2H4 was examined as a reductant using activated-carbon-supported MnOx-based catalyst in low-temperature SCR operation. Its sensitivity to Mn concentration and operating temperature was parametrically studied, the results of which showed that the catalyst activity followed the order of 130 °C > 150 °C > 180 °C with an optimized Mn concentration near 3.0 wt.%. However, rapid deactivation of catalytic activity also occurred when using C2H4 as the reductant. The mechanism of deactivation was explored and is discussed herein in which deactivation is attributed to two factors. The manganese oxide was reduced to Mn3O4 during reaction testing, which contained relatively low activity compared to Mn2O3. Also, increased crystallinity of the reduced manganese and the formation of carbon black occurred during SCR reaction testing, and these constituents on the catalyst’s surface blocked pores and active sites from participating in catalytic activity.

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Low-temperature SCR of NO with NH3 over CeO2 supported on modified activated carbon fibers

Catalysis Communications ◽

10.1016/j.catcom.2010.10.028 ◽

2011 ◽

Vol 12 (6) ◽

pp. 394-398 ◽

Cited By ~ 52

Author(s):

Lili Zhu ◽

Bichun Huang ◽

Wenhui Wang ◽

Zhengle Wei ◽

Daiqi Ye

Keyword(s):

Activated Carbon ◽

Low Temperature ◽

Carbon Fibers ◽

Activated Carbon Fibers ◽

Modified Activated Carbon ◽

Scr Of No ◽

Low Temperature Scr

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Iron doped effects on active sites formation over activated carbon supported Mn-Ce oxide catalysts for low-temperature SCR of NO

Chemical Engineering Journal ◽

10.1016/j.cej.2019.122398 ◽

2020 ◽

Vol 379 ◽

pp. 122398 ◽

Cited By ~ 18

Author(s):

Jie Yang ◽

Shan Ren ◽

Tianshi Zhang ◽

Zenghui Su ◽

Hongming Long ◽

...

Keyword(s):

Activated Carbon ◽

Low Temperature ◽

Active Sites ◽

Oxide Catalysts ◽

Scr Of No ◽

Iron Doped ◽

Low Temperature Scr

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Facile preparation of MnO2 doped Fe2O3 hollow nanofibers for low temperature SCR of NO with NH3

Journal of Materials Chemistry A ◽

10.1039/c4ta04807e ◽

2014 ◽

Vol 2 (48) ◽

pp. 20486-20493 ◽

Cited By ~ 74

Author(s):

Sihui Zhan ◽

Mingying Qiu ◽

Shanshan Yang ◽

Dandan Zhu ◽

Hongbing Yu ◽

...

Keyword(s):

Catalytic Activity ◽

Low Temperature ◽

Hollow Nanofibers ◽

Scr Of No ◽

Electrospinning Method ◽

Facile Preparation ◽

Low Temperature Scr

MnO2 doped Fe2O3 hollow nanofibers were successfully synthesized by the electrospinning method, which exhibit superior catalytic activity for low temperature NH3-SCR.

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Deactivation Effect of CaO on Mn-Ce/AC Catalyst for SCR of NO with NH3 at Low Temperature

Catalysts ◽

10.3390/catal10080873 ◽

2020 ◽

Vol 10 (8) ◽

pp. 873 ◽

Cited By ~ 1

Author(s):

Zenghui Su ◽

Shan Ren ◽

Zhichao Chen ◽

Jie Yang ◽

Yuhan Zhou ◽

...

Keyword(s):

Catalytic Activity ◽

Activated Carbon ◽

Low Temperature ◽

Acid Site ◽

Catalytic Reduction ◽

Total Pore Volume ◽

Bet Surface Area ◽

Poisoning Effect ◽

Scr Of No ◽

Critical Reason

In this study, the poisoning effect of CaO on activated carbon (AC)-based Mn-Ce catalysts was discussed. Loading CaO inhibited the catalytic activity of the catalyst and the NO conversion of the catalyst decreased from 69.5% to 38.2% at 75 °C. The amount of MnO2 in AC surface decreased in the process of loading CaO, which was detrimental to the Selective Catalytic Reduction (SCR) performance of the catalyst. The change of manganese oxide form inhibited generation rate for the chemisorption oxygen and NO2, which was the most critical reason for the decrease of catalytic activity. Besides, loaded CaO entered into the pores of the catalyst, which led to the blockage of the pores and further resulted in the decrease of the Brunauer-Emmett-Teller (BET) surface area and total pore volume. It also destroyed the oxygen-containing functional groups and acid site on the surface of AC. All of these caused the deactivation of Mn-Ce/AC catalyst after loading CaO.

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