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

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 123 ◽  
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.

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

2020 ◽  
Vol 379 ◽  
pp. 122398 ◽  
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

A comparative study of modified cotton biochar and activated carbon based catalysts in low temperature SCR

Fuel ◽  
2015 ◽  
Vol 156 ◽  
pp. 47-53 ◽  
Author(s):  
Boxiong Shen ◽  
Jianhong Chen ◽  
Shiji Yue ◽  
Guoliang Li
Keyword(s):  
Activated Carbon ◽  
Low Temperature ◽  
Comparative Study ◽  
Low Temperature Scr ◽  
Carbon Based

scholarly journals CO Oxidation over Metal Oxide (La2O3, Fe2O3, PrO2, Sm2O3, and MnO2) Doped CuO-Based Catalysts Supported on Mesoporous Ce0.8Zr0.2O2 with Intensified Low-Temperature Activity

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 724 ◽  
Author(s):  
Yan Cui ◽  
Leilei Xu ◽  
Mindong Chen ◽  
Chufei Lv ◽  
Xinbo Lian ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Co Oxidation ◽  
Active Sites ◽  
Earth Metal ◽  
High Dispersion ◽  
Impregnation Method ◽  
X Ray

CuO-based catalysts are usually used for CO oxidation owing to their low cost and excellent catalytic activities. In this study, a series of metal oxide (La2O3, Fe2O3, PrO2, Sm2O3, and MnO2)-doped CuO-based catalysts with mesoporous Ce0.8Zr0.2O2 support were simply prepared by the incipient impregnation method and used directly as catalysts for CO catalytic oxidation. These mesoporous catalysts were systematically characterized by X-ray powder diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), energy-dispersed spectroscopy (EDS) mapping, X-ray photoelectron spectroscopy (XPS), and H2 temperature programmed reduction (H2-TPR). It was found that the CuO and the dopants were highly dispersed among the mesoporous framework via the incipient impregnation method, and the strong metal framework interaction had been formed. The effects of the types of the dopants and the loading amounts of the dopants on the low-temperature catalytic performances were carefully studied. It was concluded that doped transition metal oxides could regulate the oxygen mobility and reduction ability of catalysts, further improving the catalytic activity. It was also found that the high dispersion of rare earth metal oxides (PrO2, Sm2O3) was able to prevent the thermal sintering and aggregation of CuO-based catalysts during the process of calcination. In addition, their presence also evidently improved the reducibility and significantly reduced the particle size of the CuO active sites for CO oxidation. The results demonstrated that the 15CuO-3Fe2O3/M-Ce80Zr20 catalyst with 3 wt. % of Fe2O3 showed the best low-temperature catalytic activity toward CO oxidation. Overall, the present Fe2O3-doped CuO-based catalysts with mesoporous nanocrystalline Ce0.8Zr0.2O2 solid solution as support were considered a promising series of catalysts for low-temperature CO oxidation.

Identification of active sites and reaction mechanism on low-temperature SCR activity over Cu-SSZ-13 catalysts prepared by different methods

2016 ◽  
Vol 6 (16) ◽  
pp. 6294-6304 ◽  
Author(s):  
Tao Zhang ◽  
Feng Qiu ◽  
Huazhen Chang ◽  
Xiang Li ◽  
Junhua Li
Keyword(s):  
Aqueous Solution ◽  
Reaction Mechanism ◽  
Low Temperature ◽  
Ion Exchange ◽  
Active Sites ◽  
One Pot ◽  
One Pot Synthesis ◽  
Low Temperature Scr

Cu-SSZ-13 catalysts with similar Si/Al and Cu/Al ratios were prepared by aqueous solution ion-exchange (Cu-SSZ-13-I) and one-pot synthesis (Cu-SSZ-13-O) methods.

Identification of Surface Species on Titania-Supported Manganese, Chromium, and Copper Oxide Low-Temperature SCR Catalysts

2004 ◽  
Vol 108 (28) ◽  
pp. 9927-9936 ◽  
Author(s):  
Donovan A. Peña ◽  
Balu S. Uphade ◽  
Ettireddy P. Reddy ◽  
Panagiotis G. Smirniotis
Keyword(s):  
Low Temperature ◽  
Copper Oxide ◽  
Surface Species ◽  
Scr Catalysts ◽  
Low Temperature Scr ◽  
Manganese Chromium

scholarly journals Preparation and performance of low temperature SCR catalyst on different Supports

2019 ◽  
Vol 252 ◽  
pp. 042023
Author(s):  
Dingsheng Chen ◽  
Yiting Li ◽  
Xiamei Zhong ◽  
Huanmu Zeng ◽  
Zhihang Chen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Scr Catalyst ◽  
And Performance ◽  
Low Temperature Scr

scholarly journals In Situ DRIFTS Investigation on CeOx Catalyst Supported by Fly-Ash-Made Porous Cordierite Ceramics for Low-Temperature NH3-SCR of NOX

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 496 ◽  
Author(s):  
Shaoxin Wang ◽  
Ziwei Chen ◽  
Beini He ◽  
Zheng Yan ◽  
Hao Wang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Supported Catalyst ◽  
Nh3 Scr ◽  
Scr Catalysts ◽  
Cordierite Ceramics ◽  
Porous Cordierite

A series of CeOx catalysts supported by commercial porous cordierite ceramics (CPCC) and synthesized porous cordierite ceramics (SPCC) from fly ash were prepared for selective catalytic reduction of NOx with ammonia (NH3-SCR). A greater than 90% NOx conversion rate was achieved by the SPCC supported catalyst at 250–300 °C when the concentration of loading precursor was 0.6 mol/L (denoted as 0.6Ce/SPCC), which is more advantageous than the CPCC supported ones. The EDS mapping results reveal the existence of evenly distributed impurities on the surface of SPCC, which hence might be able to provide more attachment sites for CeOx particles. Further measurements with temperature programmed reduction by hydrogen (H2-TPR) demonstrate more reducible species on the surface of 0.6Ce/SPCC, thus giving rise to better NH3-SCR performance at a low-temperature range. The X-ray photoelectron spectroscopy (XPS) analyses reveal that the Ce atom ratio is higher in 0.6Ce/SPCC, indicating that a higher concentration of catalytic active sites could be found on the surface of 0.6Ce/SPCC. The in situ diffused reflectance infrared fourier transform spectroscopy (DRIFTS) results indicate that the SCR reactions over 0.6Ce/SPCC follow both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. Hence, the SPCC might be a promising candidate to provide support for NH3-SCR catalysts, which also provide a valuable approach to recycling the fly ash.

Research Progress of Low-Temperature SCR DeNOx Catalysts

2013 ◽  
Vol 320 ◽  
pp. 629-638 ◽  
Author(s):  
Yun Sang Feng ◽  
Shao Guang Liu ◽  
Cheng Wu Chen ◽  
He Yong Zhao ◽  
Yu Song Xu
Keyword(s):  
Low Temperature ◽  
Active Sites ◽  
Noble Metals ◽  
Research Progress ◽  
Future Research ◽  
Affecting Factors ◽  
Medium Temperature ◽  
Denox Catalysts ◽  
Temperature Activation ◽  
Low Temperature Scr

Low-temperature SCR DeNOx process is considered to be a potential technique to meet the stringent environment regulations. It can avoid the problem such as blocking and eroding often generated in medium temperature, polluting and poisoning caused by alkali elements and so on. In this paper, a review of DeNOx catalysts about noble metals, molecular sieve, carbon-based and metal oxides catalyst was presented. The affecting factors of the low-temperature activation were comprehensively expounded, such as precursor introduction method, preparation method, supporter pretreatment and catalyst structure. Then mechanism of SO2 poisoning and effect of active compositions were analyzed. The dual effect of SO2 on the activity of low temperature catalysts mainly results from the formation of certain sulfur-containing species on catalyst surface. Water vapor decreased the number of available active sites attributed to competitive adsorption among H2O and other reactants. Moreover, the co-existence of H2O and SO2 resulted in the decrease of activity obviously. So the way to improve resistance of SO2 and H2O poisoning was summed up. Finally, future research and development directions in the developing low-temperature SCR for removal of NOx technology were proposed.

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