Synthesis and catalytic performance of Cu1Mn0.5Ti0.5O mixed oxide as low-temperature NH3-SCR catalyst with enhanced SO2 resistance

A new type of low-temperature selective catalytic reduction (SCR) catalyst, CuyMnzAl1−zOx, derived from layered double hydroxides is presented in this contribution.

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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.

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

Catalysis Letters ◽

10.1007/s10562-021-03585-w ◽

2021 ◽

Author(s):

Liyin Wang ◽

Peng Gui ◽

Yun Shen ◽

Cairong Gong ◽

Gang Xue

Keyword(s):

Low Temperature ◽

Catalytic Performance ◽

Nh3 Scr ◽

So2 Resistance

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Novel approach for a cerium-based highly-efficient catalyst with excellent NH3-SCR performance

Catalysis Science & Technology ◽

10.1039/c4cy00926f ◽

2014 ◽

Vol 4 (10) ◽

pp. 3611-3614 ◽

Cited By ~ 25

Author(s):

Haili Huang ◽

Wenpo Shan ◽

Shijian Yang ◽

Jinhua Zhang

Keyword(s):

Low Temperature ◽

Catalytic Performance ◽

Efficient Catalyst ◽

Scr Catalyst ◽

Highly Efficient ◽

Nh3 Scr ◽

Novel Approach ◽

Operational Temperature ◽

Temperature Window ◽

Excellent Catalytic Performance

A highly-efficient NH3-SCR catalyst, CeO2/WO3–TiO2, was prepared by a novel stepwise precipitation approach. This catalyst showed excellent catalytic performance with superior low-temperature activity, high N2 selectivity and a broad operational temperature window.

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NOx Removal by Selective Catalytic Reduction with Ammonia over a Hydrotalcite-Derived NiFe Mixed Oxide

Catalysts ◽

10.3390/catal8090384 ◽

2018 ◽

Vol 8 (9) ◽

pp. 384 ◽

Cited By ~ 18

Author(s):

Ruonan Wang ◽

Xu Wu ◽

Chunlei Zou ◽

Xiaojian Li ◽

Yali Du

Keyword(s):

Selective Catalytic Reduction ◽

Calcination Temperature ◽

Mixed Oxide ◽

Catalytic Reduction ◽

Catalytic Performance ◽

Mixed Oxide Catalysts ◽

Nh3 Scr ◽

Redox Capacity ◽

So2 Resistance ◽

Catalytic Stability

A series of NiFe mixed oxide catalysts were prepared via calcining hydrotalcite-like precursors for the selective catalytic reduction of nitrogen oxides (NOx) with NH3 (NH3-SCR). Multiple characterizations revealed that catalytic performance was highly dependent on the phase composition, which was vulnerable to the calcination temperature. The MOx phase (M = Ni or Fe) formed at a lower calcination temperature would induce more favorable contents of Fe2+ and Ni3+ and as a result contribute to the better redox capacity and low-temperature activity. In comparison, NiFe2O4 phase emerged at a higher calcination temperature, which was expected to generate more Fe species on the surface and lead to a stable structure, better high-temperature activity, preferable SO2 resistance, and catalytic stability. The optimum NiFe-500 catalyst incorporated the above virtues and afforded excellent denitration (DeNOx) activity (over 85% NOx conversion with nearly 98% N2 selectivity in the region of 210–360 °C), superior SO2 resistance, and catalytic stability.

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Enhanced Catalytic Performance of Hierarchical MnOx/ZSM-5 Catalyst for the Low-Temperature NH3-SCR

Catalysts ◽

10.3390/catal10030311 ◽

2020 ◽

Vol 10 (3) ◽

pp. 311 ◽

Cited By ~ 1

Author(s):

Jing Shao ◽

Shuyuan Cheng ◽

Zhaoxu Li ◽

Bichun Huang

Keyword(s):

Low Temperature ◽

Pore Structure ◽

Catalytic Reduction ◽

Surface Acidity ◽

Ammonium Hydroxide ◽

Catalytic Performance ◽

Nh3 Scr ◽

Hierarchical Pore Structure ◽

So2 Resistance ◽

Hierarchical Pore

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.

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Catalytic performance of Co–Fe mixed oxide for NH3-SCR reaction and the promotional role of cobalt

RSC Advances ◽

10.1039/c6ra12025c ◽

2016 ◽

Vol 6 (70) ◽

pp. 66169-66179 ◽

Cited By ~ 16

Author(s):

Changzhi Shao ◽

Xiaofei Liu ◽

Dongmei Meng ◽

Qian Xu ◽

Yanglong Guo ◽

...

Keyword(s):

Iron Oxide ◽

Citric Acid ◽

Low Temperature ◽

Mixed Oxide ◽

Catalytic Performance ◽

Nh3 Scr ◽

Acid Method ◽

Scr Of No

Co-modified iron oxide (Co-FeOx) catalysts were prepared by a citric acid method for the low temperature NH3-SCR of NO in the presence of O2.

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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.

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