scholarly journals Selective Catalytic Reduction of NO by NH3 Using a Combination of Non-Thermal Plasma and Mn-Cu/ZSM5 Catalyst

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1044
Author(s):  
Tao Zhu ◽  
Xing Zhang ◽  
Wenfeng Niu ◽  
Yatao Liu ◽  
Bo Yuan ◽  
...  

Dielectric barrier discharge (DBD) could generate non-thermal plasma (NTP) with the advantage of fast reactivity and high energy under atmosphere pressure and low-temperature. The presented work investigated the selective catalytic reduction (SCR) of nitric oxide (NO) using a combination of NTP and an Mn-Cu/ZSM5 catalyst with ammonia (NH3) as a reductant. The experimental results illustrate that the plasma-assisted SCR process enhances the low-temperature catalytic performance of the Mn-Cu/ZSM5 catalyst significantly, and it exhibits an obvious improvement in the NO removal efficiency. The reaction temperature is maintained at 200 °C in order to simulate the exhaust temperature of diesel engine, and the 10% Mn-8% Cu/ZSM5 catalyst shows the highest NO removal performance with about 93.89% at an energy density of 500 J L−1 and the selectivity to N2 is almost 99%. The voltage, frequency and energy density have a positive correlation to NO removal efficiency, which is positively correlated with the power of NTP system. In contrast, the O2 concentration has a negative correlation to the NO removal, and the NO removal efficiency cannot be improved when the NO removal process reaches reaction equilibrium in the NTP system.

RSC Advances ◽  
2017 ◽  
Vol 7 (39) ◽  
pp. 24177-24187 ◽  
Author(s):  
Haidi Xu ◽  
Mengmeng Sun ◽  
Shuang Liu ◽  
Yuanshan Li ◽  
Jianli Wang ◽  
...  

The calcined temperature of the carrier obviously affected SCR activity of catalysts, WO3/Ce0.68Zr0.32O2-500 showed the best low-temperature NH3-SCR activity due to its more Lewis acid sites and stronger redox property.


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1423
Author(s):  
Marwa Saad ◽  
Agnieszka Szymaszek ◽  
Anna Białas ◽  
Bogdan Samojeden ◽  
Monika Motak

The goal of the study was to modify activated carbon (AC) with nitrogen groups and ceria and to test the obtained materials in low temperature selective catalytic reduction of nitrogen oxides. For that purpose, the starting AC was oxidized with HNO3 of various concentrations, modified with urea and doped with 0.5 wt.% of Ce. It was observed that the increased concentration of acid influenced the catalytic activity, since textural and surface chemistry of activated carbon was changed. The most active sample was that modified with 14 M HNO3 and it reached 96% of NO conversion at 300 °C. Additionally, the addition of Ce improved the catalytic performance of modified AC, and NO was reduced according to oxidation–reduction mechanism, characteristic for supported metal oxides. Nevertheless, the samples promoted with Ce emitted significantly higher amount of CO2 comparing to the non-promoted ones.


2011 ◽  
Vol 356-360 ◽  
pp. 974-979 ◽  
Author(s):  
Xian Long Zhang ◽  
Bo Wen Shi ◽  
Xue Ping Wu ◽  
Wei Ping Jiang ◽  
Bao Jun Yang ◽  
...  

Palygorskite supported manganese oxide catalysts (MnOx/PG) were prepared for lower temperature selective catalytic reduction (SCR) of NOx by NH3. Catalyst’s SCR activity was estimated at varied temperatures. Catalyst’s properties were characterized by XRD, NH3adsorption and TPD. Results showed that MnOx/PG catalyst was highly active for SCR at low-temperature. It was also found that NH3 was mainly adsorbed on palygorskite in two forms. Weakly adsorbed NH3, which was seldom inhibited by loading of MnOx, but was more favorable to SCR. Whereas strongly adsorbed NH3was more likely to be inhibited by MnOx loading but was inessential for SCR.


2021 ◽  
Vol 11 (19) ◽  
pp. 8815
Author(s):  
Xiu Xiao ◽  
Yu Guo ◽  
Zongyu Wang ◽  
Wei Zhang ◽  
Jifeng Zhang ◽  
...  

In this paper, an experimental setup was established to study the influence of potassium chloride (KCL) solution as the ground electrode on the nitrogen oxides (NOx) removal efficiency in non-thermal plasma (NTP) generated by dielectric barrier discharging (DBD) reactor. The experimental results show that the KCL solution as the ground electrode has better stability and higher discharge intensity and it is a promising approach to improve NOx removal efficiency. The specific NOx removal efficiency is related to the power frequency, the concentration and temperature of the KCL solution. As the power frequency increases, the NOx removal efficiency first increases and then decreases, and a maximum value is reached at the power frequency of 8 kHz. The NO removal effect is improved as the concentration of the KCL solution increases, especially when the concentration is lower than 0.1 mol/L. Under the same KCL solution concentration and input energy density, the NOx removal efficiency is increased with the solution temperature. In particular, when the power discharge frequency is 8 kHz, the KCL solution concentration is 0.1 mol/L and the solution temperature is 60 °C, the NOx and NO removal efficiency reach 85.82% and 100%, respectively.


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