Experimental Study on Preparation and Operating Conditions over a Promising Monolithic Catalysts for NOx Removal: MnOx/TiO2/Cordierite

2017 ◽  
Vol 898 ◽  
pp. 1905-1915 ◽  
Author(s):  
Kai Qi ◽  
Jun Lin Xie ◽  
Feng Xiang Li ◽  
Feng He
Keyword(s):  
Low Temperature ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
Operating Conditions ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Scope Of Application ◽  
Catalyst Dosage ◽  
Cordierite Honeycomb ◽  
Low Temperature Scr

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.

Influence of Fe Doping on Ce-Mn/TiO2-ZrO2 Catalysts for Low-Temperature Selective Catalytic Reduction of NO

2014 ◽  
Vol 898 ◽  
pp. 447-451 ◽  
Author(s):  
Yun Xiao Teng ◽  
Cun Yi Song ◽  
Xi Ning Lu ◽  
Zhen Song Tong ◽  
Yu San Qin
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
Molar Ratio ◽  
Fe Doping ◽  
Reduction Of No ◽  
No Conversion ◽  
Scr Of No ◽  
Fe Catalysts

Fe-Ce-Mn catalysts loaded on TiO2-ZrO2materials were prepared by sol-gel method and then were investigated for low temperature selective catalytic reduction (SCR) of NO with NH3. It was found that the NO conversions over Fe-Ce-Mn/TiO2-ZrO2was slightly improved compared with that over Ce-Mn/TiO2-ZrO2. The results showed that 96% NO conversion was obtained over Fe-Ce-Mn/TiO2-ZrO2with the molar ratio of Fe/Mn=0.3. A comparative study of Fe-Ce-Mn/TiO2- ZrO2and Ce-Mn/TiO2-ZrO2for NO conversions at 140°C in the presence of H2O and SO2proved that Fe-Ce-Mn/TiO2-ZrO2exhibited higher resistance to H2O and SO2than that of without Fe catalysts. In addition, Fe-Ce-Mn/TiO2-ZrO2presented 90.49% NO conversion after cutting off the injection of SO2and H2O.

Selective Catalytic Reduction of NOx on VCuMn/TiO2 at Middle-Low Temperature

2012 ◽  
Vol 550-553 ◽  
pp. 128-131
Author(s):  
Zhi Hang Chen ◽  
Zhi Xiong Tang ◽  
Chao Ping Cen ◽  
Huan Mu Zeng ◽  
Ding Sheng Chen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Catalytic Reduction ◽  
Space Velocity ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Sulfur Resistance ◽  
X Ray ◽  
High Sulfur Content ◽  
Scr Of No ◽  
Low Temperature Scr

In this dissertation, combinatorial chemistry was adopted, and the activities of a series of VCuMn/TiO2catalysts prepared by impregnation method for middle-low temperature SCR of NOxwere evaluated. The activity datas showed that 2V2Cu8Mn/TiO2exhibited better activity. At 200 °C, above 70% NOxconversion were both obtained with a gas hourly space velocity of 60,000 h-1, and NOxconversion of 2V2Cu8Mn/TiO2reached nearly 100% at 275~325 °C. The X-ray diffraction characterization showed that the CuO and Mn2O3phases in VCuMn/TiO2catalysts were the main active site and with better SCR activity at middle-low temperature. In addition, sulfur-resistance of VCuMn/TiO2catalysts were investigated, NOxconversion on 2V2Cu8Mn/TiO2was above 60% at 250 °C after feeding SO2(600 ppm). It can be concluded that the modified VCu/TiO2catalyst by adding manganese obtained a good de-NOxactivity in a high sulfur content gas stream.

Fe and Mn mixed oxide catalysts supported on Sn-modified TiO2 for the selective catalytic reduction of NO with NH3 at low temperature

2022 ◽  
Author(s):  
Zhitao Han ◽  
Huan Du ◽  
Duo Xu ◽  
Yu Gao ◽  
Shaolong Yang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Mixed Oxide ◽  
Catalytic Reduction ◽  
Oxide Catalysts ◽  
Reduction Of No ◽  
Sn Doping ◽  
Mixed Oxide Catalysts ◽  
Fe And Mn ◽  
Low Temperature Scr

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.

Influence Factors of Denitration Study on Catalyst Mn-Ce/TiO2

2013 ◽  
Vol 634-638 ◽  
pp. 526-530
Author(s):  
Chun Xiang Geng ◽  
Qian Qian Chai ◽  
Wei Yao ◽  
Chen Long Wang
Keyword(s):  
Reaction Temperature ◽  
Catalytic Reduction ◽  
Removal Rate ◽  
Load Capacity ◽  
Fixed Bed ◽  
Influence Factors ◽  
Space Velocity ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Ammonia Gas

Selective Catalytic Reduction (SCR) processes have been one of the most widely used denitration methods at present and the property of low tempreture catalyst becomes a hot research. The Mn-Ce/TiO2 catalyst was prepared by incipient impregnation method. The influence of load capacity, reaction temperature, O2 content, etc. on denitration were studied by a fixed bed catalyst reactor with ammonia gas. Results showed that catalyst with load capacity 18% performed high NO removal rate of 90% at conditions of reaction temperature 160°C, low space velocity, NH3/NO molar ratio 1: 1, O2 concentration 6%.

Microstructure of Porous V2O-CeO2-SiO2 Catalyst for SCR of NO with NH3 at Low Temperature

2014 ◽  
Vol 875-877 ◽  
pp. 213-217 ◽  
Author(s):  
Mohd Razali Sohot ◽  
Umi Sarah Jais ◽  
Muhd Rosli Sulaiman
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
Reduction Process ◽  
No Emission ◽  
Scr Of No ◽  
Before And After ◽  
The Right ◽  
Proven Method

Selective catalytic reduction (SCR) is a well-proven method to reduce NO emission. However, to choose the right catalyst that provides a surface for reaction between NO and ammonia at low temperatures is a challenging task for a catalysts developers. In an earlier study, we prepared V2O5-CeO2-SiO2 catalyst with increasing V2O5 content by sol-gel route and found that the catalytic activity improved with increasing the V2O5 loading up to 0.5%. The catalytic activity, however, dropped when V2O5 loading was about 1% and increased back when the loading of V2O5 was about 5%. In this study, we looked into the microstructural relationship to explain these findings. The microstructures of the catalysts before and after exposure to NO gas revealed that the catalysts with 0.2% and 0.5% V2O5 were more porous after the reduction process possibly due to improved breakdown of (NH4)HCO3 to NH3 by the possible interaction with the V2O5 and CeO2-containing catalysts which consequently resulted in a more efficient NO reduction to N2 and H2O at low temperature. The microstructure of the catalyst with 1% V2O5 content to 5%, improved back the efficiency although clogging by CeVO4 phase still possible due to its presence based on XRD. The well-ordered micropores before exposure to NO and the more efficient breakdown of (NH4)HCO3 could have contributed to increase back the catalytic activity at low temperature.

Preparation and Characterization of MnOX-CeO2/TiO2 Catalytic Material for SCR of NOX with NH3 at Low Temperature

2013 ◽  
Vol 743-744 ◽  
pp. 198-203
Author(s):  
Qi Dong Liu ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Ya Li Wang ◽  
Yun Feng Zhang
Keyword(s):  
Low Temperature ◽  
Surface Concentration ◽  
Manganese Chloride ◽  
Molar Ratio ◽  
Manganese Acetate ◽  
Impregnation Method ◽  
Manganese Nitrate ◽  
Catalytic Materials ◽  
Scr Of No ◽  
Catalytic Material

The MnOX-CeO2/TiO2 catalytic material for low temperature SCR of NOX with NH3 was prepared using aqueous solutions of three manganese salt as well as cerous nitrate and TiO2(anatase) powder by impregnation method. The properties of the catalytic materials were investigated by TG-DSC, XRF, XRD, XPS, BET and SEM. And the low temperature catalytic activity of the catalytic materials was measured. The results showed that, when manganese nitrate and manganese chloride and manganese acetate were used as precursors, respectively, the primary phases of catalytic materials were MnOx/MnO2, MnO2/Mn8O10Cl3 and Mn3O4/MnO2, the surface Mn/Ti molar ratio were 0.68, 0.19 and 0.88, the surface area were 45.1m2/g, 25.1 m2/g and 48.6 m2/g ,respectively. The optimum NOX conversion rate of catalytic material from manganese nitrate precursor and manganese chloride precursor and manganese acetate precursor were 97.9% at 483K, 86.6% at 513K, 97.2% at 423K, respectively. Consequently, the higher low-temperature activity of MnOX-CeO2/TiO2 from manganese acetate precursor may be attributed to higher surface and higher surface concentration of activity component.

Iron-Zircon Pigments Prepared by Non-Hydrolytic Sol-Gel Method at Low Temperature

2011 ◽  
Vol 412 ◽  
pp. 223-226 ◽  
Author(s):  
Wei Hui Jiang ◽  
Yan Hui Yang ◽  
Qing Xia Zhu ◽  
Jian Min Liu
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Ferric Chloride ◽  
Lithium Fluoride ◽  
Sol Gel ◽  
Zircon Crystal ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Anhydrous Ferric Chloride

ron-zircon pigment has been synthesized by non-hydrolytic sol-gel method using zirconium chloride and tetraethoxysilane as precursors, anhydrous ferric chloride as colorant, lithium fluoride as mineralizer and anhydrous ethanol as solvent. Iron-zircon pigment has been characterized by means of DTA-TG, XRD, Colorimeter and TEM. The results show that only a small fraction of iron is incorporated in the zircon crystal structure while the remaining iron cations are trapped within the zircon matrix. The iron-zircon with the red value (a*) of 20.64 can be synthesized at 700°C with the optimum Fe/Zr molar ratio of 0.2.

Preparation and Performance of Several Non-Precious Metal Oxides Catalysts for the Low Temperature SCR of NOx with NH3

2011 ◽  
Vol 356-360 ◽  
pp. 1528-1534
Author(s):  
Wei Fang Dong
Keyword(s):  
Low Temperature ◽  
Metal Oxides ◽  
Flue Gas ◽  
Precious Metal ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Low Temperature Scr ◽  
Scr Of Nox

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.

The Effect of Doping Ce and Fe on the Mn/TiO2 Catalyst for Low Temperature NO Selective Catalytic Reduction with NH3

2012 ◽  
Vol 260-261 ◽  
pp. 1041-1046 ◽  
Author(s):  
Shi Ye Feng ◽  
Pan Gao ◽  
Chang Qing Dong ◽  
Qiang Lu
Keyword(s):  
Iron Oxide ◽  
Low Temperature ◽  
Titanium Oxide ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Reduction Of No ◽  
X Ray ◽  
Cerium Oxides ◽  
Oxide Support

A series of manganese-cerium oxide support titanium oxide with different Fe/Ti, Ce/Ti ratio were investigated for selectivity catalytic reduction of NO low at temperature with NH3 as a reducing agent. The catalysts base Mn/TiO2were prepared by sol-gel. The effect of amount of Ce and Fe oxide on the NO conversion of Mn/TiO22was studied. X-ray diffraction (XRD), temperature program desorption (TPD) were carried out. It was known that cerium oxides and iron oxide promoted preformance of Mn/TiO2 for low temperature. because Lewis is mainly take important role in the reaction for low temperature.

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