scholarly journals Catalytic Properties of Pd Modified Cu/SAPO-34 forNOxRemoval from Diesel Engine

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. C. Wang ◽  
H. Qiao ◽  
L. N. Han ◽  
Y. Q. Zuo ◽  
L. P. Chang ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Catalytic Properties ◽  
Catalytic Reduction ◽  
Aging Treatment ◽  
No Conversion ◽  
Morphology And Structure ◽  
Skeleton Structure

The Cu/SAPO-34 catalysts with different Cu contents were prepared by in situ hydrothermal synthesis. The selected Cu/SAPO-34 was modified by impregnating 1 wt% Pd(NO3)3. The morphology and structure of the samples were characterized via XRD and SEM techniques. The effects of Cu contents and the Pd modification on the de-NOxactivity of the samples were investigated through the selective catalytic reduction by C3H6and NH3. The Cu contents do not change the skeleton structure of the SAPO-34 crystalline and the Cu/SAPO-34 catalysts with Cu/Si ratios of 0.05, 0.1, and 0.2 have better de-NOxactivity than other catalysts. The addition of Pd can improve the de-NOxactivity of the Cu/SAPO-34 catalysts. The maximum of NO conversion of samples with Pd could reach 90%. Besides, the effect of aging treatment for Cu/SAPO-34 catalysts with and without Pd on the de-NOxactivity was also investigated. The results indicated that the Cu/SAPO-34 catalysts modified by Pd have better antiaging performance than raw samples.

scholarly journals Physicochemical and Catalytic Properties of Vanadia/Titania Catalysts. V. Selective Catalytic Reduction of NO with NH3

2002 ◽  
Vol 20 (10) ◽  
pp. 937-945
Author(s):  
Th. El-Nabarawy ◽  
M.N. Alaya ◽  
S.A. Sayed Ahmed ◽  
A.M. Youssef
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Properties ◽  
Catalytic Reduction ◽  
Impregnation Method ◽  
Reduction Of No ◽  
No Conversion ◽  
Scr Of No ◽  
Monolayer Coverage

Vanadia/titania catalysts were prepared containing 6.0 or 8.0 wt% V2O5 via the impregnation method. The samples as prepared were calcined at 400°C or 600°C, respectively. Selective catalytic reduction (SCR) of NO with NH3 was carried out at 257°C over the prepared catalysts. NO conversion as a function of time was followed and the stationary conversion versus the amount of catalyst employed was also investigated. It was found that the vanadia/titania catalysts calcined at 400°C were more active in the SCR of NO with NH3 relative to those calcined at 600°C. This was attributed to such catalysts possessing complete monolayer coverage of vanadia on the titania substrate. It was established that V5+ was not the active vanadia species but V4+ and V3+ may act as such for the SCR of NO with NH3.

Effect on Addictives Adding of Mn-Ce/TiO2 Selective Catalytic Reduction NO by NH3 at Low-Temperature

2014 ◽  
Vol 955-959 ◽  
pp. 25-29 ◽  
Author(s):  
Bin Wu
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Conversion Efficiency ◽  
Catalytic Properties ◽  
Catalytic Reduction ◽  
Catalytic Conversion ◽  
No Conversion ◽  
Performance Results

Additives addition into Mn-Ce/TiO2 which had good low-temperature catalytic properties was studied, so as to improve its low-temperature anti-poisoning performance. Results showed that catalytic activity of Mn-Ce/TiO2 added additives V, Fe and Cu (short for Mn-M-Ce/TiO2 ) was improved all, compared with 95% NO conversion efficiency of Mn-Ce/TiO2 at temperature of 120°C, the ratio of Mn-M-Ce/TiO2 reached nearly 100%. Mn-Fe-Ce/TiO2 had the best single anti-poisoning ability, under the existence of 7% vapor, its catalytic conversion efficiency could be always kept over 90% at 120°C.The anti-SO2 poisoning ability at low-temperature reduced after adding additives Fe and Cu. catalytic conversion efficiency of Mn-Fe-Ce/TiO2 and Mn-Cu-Ce/TiO2 could be close to 90% at temperature of 180°C when water and SO2 exist simultaneously.

Comparative analysis on the effects of diesel particulate filter and selective catalytic reduction systems on a wide spectrum of chemical species emissions

2018 ◽  
Author(s):  
Z. Gerald Liu ◽  
Devin R. Berg ◽  
Thaddeus A. Swor ◽  
James J. Schauer‡
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Diesel Particulate Filter ◽  
Catalytic Reduction ◽  
Wide Spectrum ◽  
Chemical Species ◽  
Pollutant Emissions ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Aftertreatment Systems

Two methods, diesel particulate filter (DPF) and selective catalytic reduction (SCR) systems, for controlling diesel emissions have become widely used, either independently or together, for meeting increasingly stringent emissions regulations world-wide. Each of these systems is designed for the reduction of primary pollutant emissions including particulate matter (PM) for the DPF and nitrogen oxides (NOx) for the SCR. However, there have been growing concerns regarding the secondary reactions that these aftertreatment systems may promote involving unregulated species emissions. This study was performed to gain an understanding of the effects that these aftertreatment systems may have on the emission levels of a wide spectrum of chemical species found in diesel engine exhaust. Samples were extracted using a source dilution sampling system designed to collect exhaust samples representative of real-world emissions. Testing was conducted on a heavy-duty diesel engine with no aftertreatment devices to establish a baseline measurement and also on the same engine equipped first with a DPF system and then a SCR system. Each of the samples was analyzed for a wide variety of chemical species, including elemental and organic carbon, metals, ions, n-alkanes, aldehydes, and polycyclic aromatic hydrocarbons, in addition to the primary pollutants, due to the potential risks they pose to the environment and public health. The results show that the DPF and SCR systems were capable of substantially reducing PM and NOx emissions, respectively. Further, each of the systems significantly reduced the emission levels of the unregulated chemical species, while the notable formation of new chemical species was not observed. It is expected that a combination of the two systems in some future engine applications would reduce both primary and secondary emissions significantly.

scholarly journals Fe2O3 enhanced high-temperature arsenic resistance of CeO2–La2O3/TiO2 catalyst for selective catalytic reduction of NOx with NH3

RSC Advances ◽  
2021 ◽  
Vol 11 (16) ◽  
pp. 9395-9402
Author(s):  
Na Wang ◽  
Changfei Ye ◽  
Huidong Xie ◽  
Chang Yang ◽  
Jinhong Zhou ◽  
...  
Keyword(s):  
High Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Arsenic Resistance ◽  
No Conversion ◽  
Tio2 Catalyst ◽  
Reduction Of Nox ◽  
Better Than

The NO conversion of the CeLa0.5Fe0.2/Ti is obviously better than that of the commercial vanadium-based catalyst with regard to arsenic resistance and it has good N2 selectivity, and good SO2 resistance.

A Ce-Zr-Ti Oxide Catalyst for Selective Catalytic Reduction of NO with Ammonia

2014 ◽  
Vol 535 ◽  
pp. 709-712
Author(s):  
Ye Jiang ◽  
Yan Yan ◽  
Shan Bo Huang ◽  
Xiong Zhang ◽  
Xin Wei Wang ◽  
...  
Keyword(s):  
High Activity ◽  
Selective Catalytic Reduction ◽  
Oxide Catalyst ◽  
Catalytic Reduction ◽  
Space Velocity ◽  
Impregnation Method ◽  
Reduction Of No ◽  
No Conversion ◽  
Temperature Range ◽  
Ti Oxides

A Ce-Zr-Ti oxide catalyst was prepared by an impregnation method and tested for the selective catalytic reduction of NO with NH3. The Ce-Zr-Ti oxide catalyst exhibited high activity and more than 95% NO conversion was obtained within the temperature range 300-500 °C at the high gas hourly space velocity of 50,000 h-1. The addition of Zr improved the activity of Ce-Ti oxides especially at higher reaction temperatures and their resistance to SO2.

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