scholarly journals DRIFT Study on Promotion Effect of the Keggin Structure over V2O5-MoO3/TiO2 Catalysts for Low Temperature NH3-SCR Reaction

Catalysts ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 143 ◽  
Author(s):  
Rui Wu ◽  
Ningqiang Zhang ◽  
Lingcong Li ◽  
Hong He ◽  
Liyun Song ◽  
...  
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


2019 ◽  
Vol 9 (13) ◽  
pp. 2751 ◽  
Author(s):  
Weixuan Zhao ◽  
Yanghaichao Liu ◽  
Heng Wei ◽  
Renxi Zhang ◽  
Gang Luo ◽  
...  

The effects of using CH4 as an assistant reduction agent in plasma-assisted NH3–SCR were investigated. The new hybrid reaction system performed better than DBD–NH3–SCR when the O2 concentration varied from 2% to 12%. Compared with DBD–NH3–SCR, DBD–NH3–CH4–SCR (NH3:CH4 = 1:1) showed a more significant promotion effect on the performance and N2 selectivity for NOX abatement. When the O2 concentration was 6% and the SIE was 512 J/L, the NO removal efficiency of the new hybrid system reached 84.5%. The outlet gas components were observed via FTIR to reveal the decomposition process and its mechanism. This work indicated that CH4, as an assistant agent, enhances DBD–NH3–SCR in excess oxygen to achieve a new process with significantly higher activity at a low temperature (≤348 K) for NOX removal.


RSC Advances ◽  
2015 ◽  
Vol 5 (44) ◽  
pp. 35155-35165 ◽  
Author(s):  
Meiqing Shen ◽  
Chenxu Li ◽  
Jianqiang Wang ◽  
Lili Xu ◽  
Wulin Wang ◽  
...  

The promotion effect of Cu on the V/WTi catalyst for the selective catalytic reduction of NOx by NH3 was investigated in the temperature range of 150–400 °C.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 618
Author(s):  
Huan Du ◽  
Zhitao Han ◽  
Xitian Wu ◽  
Chenglong Li ◽  
Yu Gao ◽  
...  

Er-modified FeMn/TiO2 catalysts were prepared through the wet impregnation method, and their NH3-SCR activities were tested. The results showed that Er modification could obviously promote SO2 resistance of FeMn/TiO2 catalysts at a low temperature. The promoting effect and mechanism were explored in detail using various techniques, such as BET, XRD, H2-TPR, XPS, TG, and in-situ DRIFTS. The characterization results indicated that Er modification on FeMn/TiO2 catalysts could increase the Mn4+ concentration and surface chemisorbed labile oxygen ratio, which was favorable for NO oxidation to NO2, further accelerating low-temperature SCR activity through the “fast SCR” reaction. As fast SCR reaction could accelerate the consumption of adsorbed NH3 species, it would benefit to restrain the competitive adsorption of SO2 and limit the reaction between adsorbed SO2 and NH3 species. XPS results indicated that ammonium sulfates and Mn sulfates formed were found on Er-modified FeMn/TiO2 catalyst surface seemed much less than those on FeMn/TiO2 catalyst surface, suggested that Er modification was helpful for reducing the generation or deposition of sulfate salts on the catalyst surface. According to in-situ DRIFTS the results of, the presence of SO2 in feeding gas imposed a stronger impact on the NO adsorption than NH3 adsorption on Lewis acid sites of Er-modified FeMn/TiO2 catalysts, gradually making NH3-SCR reaction to proceed in E–R mechanism rather than L–H mechanism. DRIFTS.


2021 ◽  
Vol 49 (1) ◽  
pp. 113-120
Author(s):  
Dong-jie YAN ◽  
Tong GUO ◽  
Ya YU ◽  
Zhao-hui CHEN

Fuel ◽  
2021 ◽  
Vol 303 ◽  
pp. 121239
Author(s):  
Zhiping Zhang ◽  
Yingying Li ◽  
Piaoping Yang ◽  
Yushi Li ◽  
Chen Zhao ◽  
...  

2021 ◽  
Vol 9 (5) ◽  
pp. 106323
Author(s):  
Yuhan Zhou ◽  
Buxin Su ◽  
Shan Ren ◽  
Zhichao Chen ◽  
Zenghui Su ◽  
...  

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