scholarly journals Enhancing the Water Resistance of Mn-MOF-74 by Modification in Low Temperature NH3-SCR

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1004 ◽  
Author(s):  
Sheng Wang ◽  
Qiang Gao ◽  
Xiuqin Dong ◽  
Qianyun Wang ◽  
Ying Niu ◽  
...  

In this study, Mn-MOF-74 was successfully synthesized and further modified via two paths for enhanced water resistance. The structure and morphology of the modified samples were investigated by a series of characterization methods. The results of selective catalytic reduction (SCR) performance tests showed that polyethylene oxide-polypropylene-polyethylene oxide (P123)-modified Mn-MOF-74 exhibited outstanding NO conversion of up to 92.1% in the presence of 5 vol.% water at 250 °C, compared to 52% for Mn-MOF-74 under the same conditions. It was concluded that the water resistance of Mn-MOF-74 was significantly promoted after the introduction of P123 and that the unmodified P123-Mn-MOF-74 was proven to be a potential low-temperature SCR catalyst.

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1020
Author(s):  
Yizhe Helian ◽  
Suping Cui ◽  
Xiaoyu Ma

Selective catalytic reduction (SCR) technology is the most widely used flue gas denitration technology at present. The stability of a catalyst is the main factor limiting the development of this technology. In this study, an environmentally friendly and highly efficient NH3-SCR catalyst was prepared by coprecipitation method from acidolysis residue of industrial waste and tourmaline. We found that the addition of tourmaline has an important impact on the denitration activity of the catalytic material. The NOx conversion exceeded 97% at 200 °C with the dosage of 10% tourmaline, which is about 7% higher than that without doping. The improvement of catalytic performance was mostly attributed to the permanent electrodes of tourmaline, which effectively promotes the dispersion of MnOx/TiO2 catalytic materials, increases the number of acidic sites and changes the valence distribution of manganese ions in products, which speeds up the diffusion of protons and ions, resulting in the acceleration of redox reaction. These as-developed tourmaline-modified MnOx/TiO2 materials have been demonstrated to be promising as a new type of highly efficient low-temperature NH3-SCR catalyst.


2018 ◽  
Vol 47 (9) ◽  
pp. 2992-3004 ◽  
Author(s):  
Qinghua Yan ◽  
Sining Chen ◽  
Lei Qiu ◽  
Yanshan Gao ◽  
Dermot O'Hare ◽  
...  

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


2022 ◽  
Author(s):  
Zhitao Han ◽  
Huan Du ◽  
Duo Xu ◽  
Yu Gao ◽  
Shaolong Yang ◽  
...  

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.


Author(s):  
Jae Gu Heo ◽  
Mahboob Ullah ◽  
Myoung-Pyo Chun ◽  
Yong Sik Chu ◽  
Seong Gwan Seo ◽  
...  

2017 ◽  
Vol 898 ◽  
pp. 1905-1915 ◽  
Author(s):  
Kai Qi ◽  
Jun Lin Xie ◽  
Feng Xiang Li ◽  
Feng He

The samples of MnOx/TiO2 catalysts supported on cordierite honeycomb ceramics were prepared by a sol-gel-impregnation method, and evaluated for low-temperature (353-473 K) selective catalytic reduction (SCR) of NOx with NH3. The influences of pretreatment on cordierite and catalyst dosage were investigated at first and optimized as follows: pickling for cordierite honeycomb ceramics with 1 mol/L HNO3 for 3 h prior to loading procedure as well as the catalyst dosage of 3-5 wt.%. The activity results indicated that there was an optimum working condition for MnOx/TiO2/cordierite catalysts: NH3/NO molar ratio=1.1, [O2]=3 vol.%, GHSV=5514 h-1, the highest activity of nearly 100% NO conversion could be obtained. As a comparison, the performances of commercialized vanadium-based honeycomb catalyst were also employed, which revealed the narrower scope of application of GHSV and the higher active temperature window. In conclusion, it turns out that the prepared MnOx/TiO2/cordierite catalysts are more applicable as a low-temperature SCR catalyst for NOx removal in a more complicated application environment.


RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 40047-40054
Author(s):  
Qizhi Chen ◽  
Yong Yang ◽  
Hang Luo ◽  
Zuohua Liu ◽  
Zhangfa Tong ◽  
...  

Ce modified MnOx/SAPO-34 was prepared and investigated for low-temperature selective catalytic reduction of NOx with ammonia (NH3-SCR).


RSC Advances ◽  
2017 ◽  
Vol 7 (75) ◽  
pp. 47570-47582 ◽  
Author(s):  
Haidi Xu ◽  
Qingjin Lin ◽  
Yun Wang ◽  
Li Lan ◽  
Shuang Liu ◽  
...  

Optimal WO3substituted by Nb2O5could obviously improve the low-temperature NH3-SCR activity of WO3/Ce0.68Zr0.32O2, and the Nb-substituted catalyst showed excellent SO2and H2O tolerance could be a promising candidate for NH3-SCR catalyst.


2011 ◽  
Vol 356-360 ◽  
pp. 1528-1534
Author(s):  
Wei Fang Dong

A series of non-precious metal oxides catalysts were prepared for low-temperature selective catalytic reduction (SCR) of NOx with NH3 in a fixed bed reactor. The catalytic performance was evaluated by the removal efficiency of NOx and N2selectivity which were respectively detected by flue gas analyzer and flue gas chromatograph. Furthermore, the components of gas products from the above experiments were analysed with 2010 GC-MS. The results illustrated that the MnO2exhibited the highest NOx conversion to 95.46% and the highest selectivity of N2to 100% at temperature of 393K, then followed ZrO2, Al2O3and Fe2O3.


2018 ◽  
Vol 148 (4) ◽  
pp. 1228-1235 ◽  
Author(s):  
Rui Wu ◽  
Ningqiang Zhang ◽  
Xiaojun Liu ◽  
Lingcong Li ◽  
Liyun Song ◽  
...  

Abstract Heteropolyacids and their salts have been effectively used in selective catalytic reduction because of the Keggin structure and extraordinarily strong acidity. Catalysts with and without the Keggin structure were synthesized to further investigate the effects of heteropolyoxometallate on low temperature NH3–SCR. XRD, BET, Raman, H2–TPR, NH3–TPD, FT-IR, and SO2–TPD techniques were used to characterize the physicochemical characteristics of the catalysts. Results indicate that catalysts with the Keggin structure had more surface Brönsted and Lewis acid sites, and these catalysts had significantly improved performances in the SCR reaction and in SO2 poisoning resistance. Graphical Abstract


Author(s):  
Dingsheng Chen ◽  
Yiting Li ◽  
Xiamei Zhong ◽  
Huanmu Zeng ◽  
Zhihang Chen ◽  
...  

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