Investigation and Preparation of the SCR Catalysts Nano-Co/Ce-V-Zr-TiO2

2010 ◽  
Vol 663-665 ◽  
pp. 1097-1102
Author(s):  
Xiu Feng Ren ◽  
Fen Wang ◽  
Yuan Zhou ◽  
Hong En Nian ◽  
Yu Na Pang ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
Selective Reduction ◽  
Catalytic Performance ◽  
Scr Catalysts ◽  
Selective Reduction Of Nox ◽  
Reduction Of Nox ◽  
Co Precipitation ◽  
Catalytic Performances

The nano-Co/Ce-V-Zr-TiO2 catalysts with the selective catalytic reduction (SCR) were prepared by methods of Sol-gel, impregnation (IM) and co-precipitation (CP). The phase compositions, microstructures and specific surface area of the catalysts were analyzed by BET, XRD and SEM, respectively. The effect of CeO2, CoO, V2O5 and V2O5 loading and reaction temperature on the catalytic performances of the as-prepared catalysts was investigated by using the selective reduction of NOx with NH3. The results showed all the as-prepared Co/Ce-V-Zr-TiO2 catalysts were made up of nanometer grains. Compared to conventional TiO2 catalysts, the as-prepared Co/Ce-V-Zr-TiO2 catalysts possessed better catalytic performance, higher adsorbability and larger area of contact with reactant, which is due to large quantity surface micropores. The NOx conversion of SCR over 8 wt%Co/Ce-V-Zr-TiO2 catalysts reached 98.3% at the reaction temperature of 550 oC. Furthermore, the activity of Co/Ce-V-Zr-TiO2 catalysts were improved by the Co loading, however, further increasing the Co loading lead to decrease the catalysis activity.

Investigation of the SCR Catalyst Ce-V/TiO2

2009 ◽  
Vol 610-613 ◽  
pp. 274-280
Author(s):  
Fen Wang ◽  
Xiu Feng Ren ◽  
Jian Feng Zhu ◽  
Hai Bo Yang
Keyword(s):  
Reaction Temperature ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
Selective Reduction ◽  
Catalytic Performance ◽  
Scr Catalyst ◽  
Nox Conversion ◽  
Selective Reduction Of Nox ◽  
Reduction Of Nox ◽  
Catalytic Performances

The Ce-V/TiO2 catalysts with the selective catalytic reduction (SCR) were prepared by method of Sol-gel and insuccation. The phase compositions, microstructures and specific surface area of the catalysts were analyzed by XRD, SEM and BET, respectively. The effect of CeO2 and V2O5 loading and reaction temperature on the catalytic performances of the as-prepared catalysts was investigated by using the selective reduction of NOx with NH3. The results showed all the as-prepared Ce-V/TiO2 catalysts were made up of nanometer grains. Compared to conventional TiO2 catalysts, the as-prepared Ce-V/TiO2 catalysts possessed better catalytic performance, higher adsorbability and larger area of contact with reactant, which is due to large quantity surface micropores. The NOx conversion of SCR over 5wt%Ce-10wt%V/TiO2 catalysts reached 96.2% at the reaction temperature of 500 oC.

scholarly journals Characterization of W-Mn-Ce-Ti Oxides Catalysts Prepared by Different Methods for Selective Reduction of NO with NH3

2021 ◽  
Author(s):  
Xiaodi Li ◽  
Zhitao Han ◽  
Qingdong Shi ◽  
Xitian Wu ◽  
Yu Gao ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Catalytic Reduction ◽  
Low Cost ◽  
Sol Gel ◽  
Selective Reduction ◽  
Acid Sites ◽  
Active Species ◽  
Activity Measurement ◽  
Reduction Of No ◽  
Scr Catalysts

Abstract Aiming to develop low cost and environmentally friendly SCR catalysts, various transition metals and rare earth elements have been used and combined to prepare polymetallic oxide catalysts in recent years, which generally exhibit excellent SCR performance. Here four typical metal elements (Mn, Ce, W and Ti) have been selected to prepare polymetallic oxides (WMnCeTiOx) catalysts, and the effects of preparation methods, such as coprecipitation (CP), sol-gel (SG), and deposition precipitation (DP), on the performance of selective catalytic reduction of NO with NH3 at 160~360 ºC have been investigated systematically. Some key techniques of XRD, BET, XPS, H2-TPR, NH3-TPD and in-situ DRIFTS were used to characterize the physicochemical properties of the prepared WMnCeTiOx catalysts. The SCR activity measurement results showed that NH3-SCR activities of WMnCeTiOx catalysts prepared through coprecipitation and deposition precipitation methods exhibited much better NO removal performance in the temperature range of 160~360 ºC than that prepared via sol-gel method. More importantly, WMnCeTiOx catalysts prepared through coprecipitation method exhibited superior SO2 and H2O tolerance compared with those prepared via deposition precipitation and sol-gel methods. It demonstrated that the preparation process imposed a crucial impact on the physicochemical properties of the prepared WMnCeTiOx catalysts, thus influencing on their SCR performance. According to the characterization results, the better performance of WMnCeTiOx(CP) catalyst could be ascribed to its higher concentrations of Mn4+ and Ce3+, larger surface area and highly-dispersed active species on catalyst surface. In addition, compared with WMnCeTiOx catalysts prepared by deposition precipitation and sol-gel methods, WMnCeTiOx(CP) catalyst possessed much more surface acid sites, stronger reduction capacity and better adsorption capacity for NH3 and NO, which might also play a key role in promoting its SCR performance.

scholarly journals A CeO2/ZrO2-TiO2 Catalyst for the Selective Catalytic Reduction of NOx with NH3

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 592 ◽  
Author(s):  
Wenpo Shan ◽  
Yang Geng ◽  
Yan Zhang ◽  
Zhihua Lian ◽  
Hong He
Keyword(s):  
Selective Catalytic Reduction ◽  
Ph Value ◽  
Catalytic Reduction ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Excellent Activity ◽  
Reduction Of Nox ◽  
High Space ◽  
Catalytic Performances ◽  
High Space Velocity

In this study, CeZr0.5TiaOx (with a = 0, 1, 2, 5, 10) catalysts were prepared by a stepwise precipitation approach for the selective catalytic reduction of NOx with NH3. When Ti was added, all of the Ce-Zr-Ti oxide catalysts showed much better catalytic performances than the CeZr0.5Ox. Particularly, the CeZr0.5Ti2Ox catalyst showed excellent activity for broad temperature range under high space velocity condition. Through the control of pH value and precipitation time during preparation, the function of the CeZr0.5Ti2Ox catalyst could be controlled and the structure with highly dispersed CeO2 (with redox functions) on the surface of ZrO2-TiO2 (with acidic functions) could be obtained. Characterizations revealed that the superior catalytic performance of the catalyst is associated with its outstanding redox properties and adsorption/activation functions for the reactants.

scholarly journals Mechanistic Studies of Catalytic Reduction of Nitrogen Oxides from Diesel Engine Exhaust over Manganese and Cerium Oxide Based Catalysts

2021 ◽  
pp. 40-50
Author(s):  
Russel C. L. De Silva ◽  
Darrell P. Eyman
Keyword(s):  
Nitrogen Oxides ◽  
Catalytic Reduction ◽  
Selective Reduction ◽  
Catalyst System ◽  
Mechanistic Studies ◽  
Engine Exhaust ◽  
Catalytic Sites ◽  
Selective Reduction Of Nox ◽  
Reduction Of Nox ◽  
Cerium Catalysts

Finding a catalyst system that is effective and consistent for the selective reduction of NOx during lean exhaust conditions has been a predominant challenge to both industrial and research institutions, despite the large number of reported catalysts tested. The selective catalytic reduction of NO + NO2 (NOx) with CO and C3 hydrocarbons at low temperatures (175-225 oC) is investigated over manganese and cerium catalysts with and without the presence of a precious metal. 1% Pt/Mn/Al catalysts show promising results for the reaction, with continuous NOx conversions well more than 35% in the period extending beyond 170 hours. The synthesis technique of the catalyst and the reaction temperature greatly effects the reaction. There is no evidence of the presence of other nitrogen oxides in the products except for a very small quantity of N2O only at the beginning of the reaction. Mechanistic studies reveal manganese to be the major catalytic sites, while the platinum plays a secondary role. Mn/Ce/Al also show continuous deNOx activity with NOx conversions of 28-35%.

scholarly journals Modeling of EPR Parameters for Cu(II): Application to the Selective Reduction of NOx Catalyzed by Cu-Zeolites

2018 ◽  
Vol 61 (9-11) ◽  
pp. 810-832 ◽  
Author(s):  
Estefanía Fernández ◽  
Marta Moreno-González ◽  
Manuel Moliner ◽  
Teresa Blasco ◽  
Mercedes Boronat ◽  
...  
Keyword(s):  
Selective Reduction ◽  
Selective Reduction Of Nox ◽  
Epr Parameters ◽  
Reduction Of Nox

The selective catalytic reduction of NOx over a Cu/ZSM-5/SAPO-34 composite catalyst

RSC Advances ◽  
2015 ◽  
Vol 5 (127) ◽  
pp. 104923-104931 ◽  
Author(s):  
Jixing Liu ◽  
Weiyu Song ◽  
Chi Xu ◽  
Jian Liu ◽  
Zhen Zhao ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Mass Fraction ◽  
Catalytic Reduction ◽  
Composite Catalyst ◽  
Composite Catalysts ◽  
Scr Of No ◽  
Reduction Of Nox ◽  
Seed Method ◽  
Catalytic Performances

A series of Cu/ZSM-5/SAPO-34 composite catalysts with varying ZSM-5 mass fraction were synthesized using a pre-seed method, and their catalytic performances were tested for selective catalytic reduction (SCR) of NO with NH3.

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