scholarly journals The Poisoning Effect of Na Doping over Mn-Ce/TiO2Catalyst for Low-Temperature Selective Catalytic Reduction of NO by NH3

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Liu Yang ◽  
Yue Tan ◽  
Zhongyi Sheng ◽  
Aiyi Zhou
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Chemical Properties ◽  
Impregnation Method ◽  
Negative Effects ◽  
Poisoning Effect ◽  
Surface Areas ◽  
Physical And Chemical

Sodium carbonate (Na2CO3), sodium nitrate (NaNO3), and sodium chloride (NaCl) were chosen as the precursors to prepare the Na salts deposited Mn-Ce/TiO2catalysts through an impregnation method. The influence of Na on the performance of the Mn-Ce/TiO2catalyst for low-temperature selective catalytic reduction ofNOxby NH3was investigated. Experimental results showed that Na salts had negative effects on the activity of Mn-Ce/TiO2and the precursors of Na salts also affected the catalytic activity. The precursor Na2CO3had a greater impact on the catalytic activity, while NaNO3had minimal effect. The characterization results indicated that the significant changes in physical and chemical properties of Mn-Ce/TiO2were observed after Na was doped on the catalysts. The significant decreases in surface areas and NH3adsorption amounts were observed after Na was doped on the catalysts, which could be considered as the main reasons for the deactivation of Na deposited Mn-Ce/TiO2.

The DeNOx Characteristics of V/Ti Plate SCR Catalysts

2011 ◽  
Vol 356-360 ◽  
pp. 1712-1715
Author(s):  
Qiang Lu ◽  
Shu Hua Su ◽  
Shi Ye Fen ◽  
Wei Liang Cheng ◽  
Chang Qing Dong
Keyword(s):  
Nitric Oxide ◽  
Catalytic Activity ◽  
Selective Catalytic Reduction ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Negative Effects ◽  
V2o5 Content ◽  
Scr Catalysts

A series of V2O5/WO3/TiO2plate catalysts were prepared via the incipient wetness impregnation method, with the V2O5content of 0.68 wt%, 1.01 wt%, 1.19 wt%, 1.5 wt% and the WO3loading of 4.8 wt%, 6.2 wt%, 7.9 wt%, 9.2 wt%, respectively. Selective catalytic reduction of nitric oxide by ammonia (NH3-SCR) experiments were performed to investigate the effects of the several factors on the performance of the catalysts, including the V2O5, WO3and MoO3content in the catalysts and the O2concentration in the flue gas. The results indicated that as the rising of the V2O5 content, the SCR activity of the V2O5/WO3/TiO2catalysts was firstly increased and then slightly decreased, with the best activity obtained at the V2O5content of 1.19 wt%. As the increasing of the WO3content, the activity was firstly increased slightly and then almost kept constant. Furthermore, the loading of the MoO3on the V2O5/WO3/TiO2plate catalysts would bring negative effects to the catalytic activity. In addition, the capability of the catalysts would slightly increase as the O2concentration rising up to 7%, and then became stable at higher O2concentrations.

scholarly journals Insights into the promotion role of phosphorus doping on carbon as a metal-free catalyst for low-temperature selective catalytic reduction of NO with NH3

RSC Advances ◽  
2020 ◽  
Vol 10 (22) ◽  
pp. 12908-12919
Author(s):  
Weifeng Li ◽  
Shuangling Jin ◽  
Rui Zhang ◽  
Yabin Wei ◽  
Jiangcan Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
No Reduction ◽  
Catalytic Reduction ◽  
Carbon Aerogels ◽  
Phosphorus Doping ◽  
Reduction Of No ◽  
Metal Free

P species can effectively enhance the catalytic activity of carbon aerogels for NO reduction at low temperature.

scholarly journals The Enhanced Performance of N-Modified Activated Carbon Promoted with Ce in Selective Catalytic Reduction of NOx with NH3

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1423
Author(s):  
Marwa Saad ◽  
Agnieszka Szymaszek ◽  
Anna Białas ◽  
Bogdan Samojeden ◽  
Monika Motak
Keyword(s):  
Catalytic Activity ◽  
Activated Carbon ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Catalytic Performance ◽  
Reduction Mechanism ◽  
Modified Activated Carbon ◽  
Oxidation Reduction ◽  
Reduction Of Nox

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.

Removal of NO by Selective Catalytic Reduction with Ethylene over Catalyst Cu/ZSM-5

2011 ◽  
Vol 71-78 ◽  
pp. 2806-2813
Author(s):  
Jiang Jun Hu ◽  
Qian Ma ◽  
Ling Ouyang ◽  
Xi Chen ◽  
Fu Xing Gan
Keyword(s):  
Nitric Oxide ◽  
Catalytic Activity ◽  
Selective Catalytic Reduction ◽  
Influencing Factors ◽  
Catalytic Reduction ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Gas Concentration ◽  
Oxygen Gas ◽  
Wet Impregnation Method

The selective catalytic reduction of nitric oxide by ethylene was studied over Cu/ZSM-5 catalyst in the temperature range of 200-550°C, in which NO cannot be reduced by ethylene without Cu/ZSM-5 catalyst. Prepared Cu/ZSM-5 catalyst in varies loading as Na/ZSM-5 by the wet impregnation method, and the effect of the catalytic activity was studied in varies fitting temperatures. Several influencing factors, such as the different reaction temperatures, oxygen gas concentration, and Cu2+ concentration were investigated. Cu-Ce-ZSM-5 catalyst was prepared by wet impregnation method and the metallic influence of CeO2 to the catalytic ability was studied.

Study of Co-Mn/TiO2 SCR Catalyst at Low Temperature

2015 ◽  
Vol 1102 ◽  
pp. 11-16 ◽  
Author(s):  
Hua Hu ◽  
Jun Lin Xie ◽  
De Fang ◽  
Feng He
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Chemical Characteristics ◽  
Impregnation Method ◽  
Scr Catalyst ◽  
No Conversion ◽  
Co Doping ◽  
Phase Structures ◽  
Adsorption Capacities ◽  
Physical And Chemical

The Co-Mn/TiO2 catalysts with different contents of Co were prepared by the impregnation method. Catalytic activity tests showed that the addition of Co could obviously enhance the SCR performance of Mn/TiO2 catalyst, and the NO conversion of 0.05Co-Mn/TiO2 samples could reach 94.03% at 180 °C. At the same time, with the help of XRD, BET, H2-TPR and NH3-TPD, the various physical and chemical characteristics as well as phase structures of catalysts were characterized systematically. According to the results, the formations of crystalline CoMn2O4, Mn3O4 and amorphous Mn2O3 were detected. Furthermore, Co doping could reduce the reduction temperatures of catalysts and enhance the adsorption capacities of NH3, resulting in the excellent SCR performance at low temperature.

Studies on the Preparation and DeNOx Performance of MnxOy/CNTs Catalyst for Low-Temperature Selective Catalytic Reduction

2013 ◽  
Vol 798-799 ◽  
pp. 231-234 ◽  
Author(s):  
Bing Nan Ren ◽  
Qiao Wen Yang
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Oxide Catalyst ◽  
Catalytic Reduction ◽  
Space Velocity ◽  
Impregnation Method ◽  
Active Components ◽  
Reaction Conditions ◽  
No Conversion ◽  
Scr Of No

The metal oxide catalyst was prepared by loading MnxOyon carbon nanotubes (CNTs) with impregnation method. Then the catalyst was characterized by BET, TEM and XPS, and the catalytic activity of the catalyst for selective catalytic reduction (SCR) of NO at low-temperature was investigated. The results showed that the species of active components loaded on the catalyst were MnO2and Mn2O3. The NO conversion was improved with reduction temperature increase under 250°C, increased slowly over 250°C. The O2content had an outstanding effect on NO conversion of catalysts at a low concentration range. Once the oxygen content was enhanced over 5%, there was no significant increase in the NO conversion. With the increasing of space velocity, the NO conversion rate was decreased under the reaction conditions.

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