Effect of Tourmaline Addition on the Catalytic Performance and SO2 Resistance of NixMn3−xO4 Catalyst for NH3-SCR Reaction at Low Temperature

A ZSM-5 zeolite with a hierarchical pore structure was synthesized by the desilication-recrystallization method using tetraethyl ammonium hydroxide (TEAOH) and cetyltrimethylammonium bromide (CTAB) as the desilication and structure-directing agents, respectively. The MnOx/ZSM-5 catalyst was synthesized by the ethanol dispersion method and applied for the low-temperature selective catalytic reduction of NOx with NH3. The results showed that NOx conversion of the hierarchical MnOx/ZSM-5 catalyst could reach 100% at about 120 °C and could be maintained in the temperature range of 120–240 °C with N2 selectivity over 90%. Furthermore, the hierarchical MnOx/ZSM-5catalyst presented better SO2 resistance performance than the traditional catalyst in the presence of 100 ppm SO2 at 120 °C. XRD, SEM, TEM, XPS, BET, NH3-TPD, and TG were applied to characterize the structural properties of the MnOx/ZSM-5 catalysts. These results showed that the MnOx/ZSM-5 catalyst had micropores (0.78 nm) and mesopores (3.2 nm) leading to a larger specific surface area, which improved the mass transfer of reactants and products while reducing the formation of sulfates. The better catalytic performance over hierarchical MnOx/ZSM-5 catalyst could be attributed to the higher concentration of Mn4+ and chemisorbed oxygen species and higher surface acidity. The improved SO2 resistance was related to the catalyst’s hierarchical pore structure.

Download Full-text

Insight into the Promoting Role of Er Modification on SO2 Resistance for NH3-SCR at Low Temperature over FeMn/TiO2 Catalysts

Catalysts ◽

10.3390/catal11050618 ◽

2021 ◽

Vol 11 (5) ◽

pp. 618

Author(s):

Huan Du ◽

Zhitao Han ◽

Xitian Wu ◽

Chenglong Li ◽

Yu Gao ◽

...

Keyword(s):

Low Temperature ◽

Catalyst Surface ◽

Impregnation Method ◽

In Situ Drifts ◽

Tio2 Catalyst ◽

Nh3 Scr ◽

Nh3 Adsorption ◽

So2 Resistance ◽

Fast Scr

Er-modified FeMn/TiO2 catalysts were prepared through the wet impregnation method, and their NH3-SCR activities were tested. The results showed that Er modification could obviously promote SO2 resistance of FeMn/TiO2 catalysts at a low temperature. The promoting effect and mechanism were explored in detail using various techniques, such as BET, XRD, H2-TPR, XPS, TG, and in-situ DRIFTS. The characterization results indicated that Er modification on FeMn/TiO2 catalysts could increase the Mn4+ concentration and surface chemisorbed labile oxygen ratio, which was favorable for NO oxidation to NO2, further accelerating low-temperature SCR activity through the “fast SCR” reaction. As fast SCR reaction could accelerate the consumption of adsorbed NH3 species, it would benefit to restrain the competitive adsorption of SO2 and limit the reaction between adsorbed SO2 and NH3 species. XPS results indicated that ammonium sulfates and Mn sulfates formed were found on Er-modified FeMn/TiO2 catalyst surface seemed much less than those on FeMn/TiO2 catalyst surface, suggested that Er modification was helpful for reducing the generation or deposition of sulfate salts on the catalyst surface. According to in-situ DRIFTS the results of, the presence of SO2 in feeding gas imposed a stronger impact on the NO adsorption than NH3 adsorption on Lewis acid sites of Er-modified FeMn/TiO2 catalysts, gradually making NH3-SCR reaction to proceed in E–R mechanism rather than L–H mechanism. DRIFTS.

Download Full-text

Synergistic effect and mechanism of FeO and CeO co-doping on the superior catalytic performance and SO2 tolerance of Mn-Fe-Ce/ACN catalyst in low-temperature NH3-SCR of NO

Journal of Environmental Chemical Engineering ◽

10.1016/j.jece.2021.106360 ◽

2021 ◽

Vol 9 (6) ◽

pp. 106360

Author(s):

Lijun Jiang ◽

Ya Liang ◽

Weizao Liu ◽

Hongli Wu ◽

Tahani Aldahri ◽

...

Keyword(s):

Low Temperature ◽

Synergistic Effect ◽

Catalytic Performance ◽

Co Doping ◽

Nh3 Scr ◽

Scr Of No ◽

So2 Tolerance

Download Full-text

CeMn/TiO2 catalysts prepared by different methods for enhanced low-temperature NH3-SCR catalytic performance

Chemical Engineering Science ◽

10.1016/j.ces.2021.116588 ◽

2021 ◽

pp. 116588

Author(s):

Xianlong Zhang ◽

Xincheng Zhang ◽

Xiangjin Yang ◽

Yazhong Chen ◽

Xiaorui Hu ◽

...

Keyword(s):

Low Temperature ◽

Catalytic Performance ◽

Nh3 Scr

Download Full-text

Significantly enhanced activity and SO2 resistance of Zr-modified CeTiOx catalyst for low-temperature NH3-SCR by H2 reduction treatment

Molecular Catalysis ◽

10.1016/j.mcat.2021.112069 ◽

2022 ◽

Vol 518 ◽

pp. 112069

Author(s):

Xiaoling Wei ◽

Runqi Zhao ◽

Bingxian Chu ◽

Shangzhi Xie ◽

Qiuju qin ◽

...

Keyword(s):

Low Temperature ◽

Reduction Treatment ◽

Nh3 Scr ◽

Enhanced Activity ◽

So2 Resistance

Download Full-text

Synergistic effect of VOx and MnOx surface species for improved performance of V2O5/Ce0.5Ti0.5−xMnxO2−δ catalysts in low-temperature NH3-SCR of NO

Catalysis Science & Technology ◽

10.1039/c8cy02193g ◽

2018 ◽

Vol 8 (24) ◽

pp. 6360-6374 ◽

Cited By ~ 7

Author(s):

Thanh Huyen Vuong ◽

Stephan Bartling ◽

Ursula Bentrup ◽

Henrik Lund ◽

Jabor Rabeah ◽

...

Keyword(s):

Low Temperature ◽

Synergistic Effect ◽

Catalytic Performance ◽

Surface Species ◽

Nh3 Scr ◽

Redox Couples ◽

Scr Of No ◽

Improved Performance

Inserting adjacent Mn3+/Mn2+ and VO3+/VO2+ redox couples in Ce1−xTixO2 improves catalytic performance.

Download Full-text

The Effect of Tourmaline on SCR Denitrification Activity of MnOx/TiO2 at Low Temperature

Catalysts ◽

10.3390/catal10091020 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1020

Author(s):

Yizhe Helian ◽

Suping Cui ◽

Xiaoyu Ma

Keyword(s):

Low Temperature ◽

Catalytic Reduction ◽

Catalytic Performance ◽

Scr Catalyst ◽

Highly Efficient ◽

Nh3 Scr ◽

Catalytic Material ◽

Acidic Sites ◽

Denitrification Activity ◽

The Stability

Selective catalytic reduction (SCR) technology is the most widely used flue gas denitration technology at present. The stability of a catalyst is the main factor limiting the development of this technology. In this study, an environmentally friendly and highly efficient NH3-SCR catalyst was prepared by coprecipitation method from acidolysis residue of industrial waste and tourmaline. We found that the addition of tourmaline has an important impact on the denitration activity of the catalytic material. The NOx conversion exceeded 97% at 200 °C with the dosage of 10% tourmaline, which is about 7% higher than that without doping. The improvement of catalytic performance was mostly attributed to the permanent electrodes of tourmaline, which effectively promotes the dispersion of MnOx/TiO2 catalytic materials, increases the number of acidic sites and changes the valence distribution of manganese ions in products, which speeds up the diffusion of protons and ions, resulting in the acceleration of redox reaction. These as-developed tourmaline-modified MnOx/TiO2 materials have been demonstrated to be promising as a new type of highly efficient low-temperature NH3-SCR catalyst.

Download Full-text