Mesoporous Mn–Ti amorphous oxides: a robust low-temperature NH3-SCR catalyst

Mn–Ti amorphous oxides prepared by the combinedin situdeposition and freeze-drying strategy exhibited excellent activities and stability in low-temperature NH3-SCR.

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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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Low-temperature Shift DeNOx Activity of Nanoflake V2O5 loaded WO3/TiO2 as NH3-SCR Catalyst

Inorganic Chemistry Communications ◽

10.1016/j.inoche.2021.109191 ◽

2022 ◽

pp. 109191

Author(s):

Jae Gu Heo ◽

Mahboob Ullah ◽

Myoung-Pyo Chun ◽

Yong Sik Chu ◽

Seong Gwan Seo ◽

...

Keyword(s):

Low Temperature ◽

Temperature Shift ◽

Scr Catalyst ◽

Nh3 Scr

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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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New Insight into the Effects of NH3 on SO2 Poisoning for In Situ Removal of Metal Sulfates in Low-Temperature NH3-SCR over an Fe–V Catalyst

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.0c04902 ◽

2020 ◽

Vol 124 (39) ◽

pp. 21396-21406

Author(s):

Jincheng Mu ◽

Xinyong Li ◽

Xinyang Wang ◽

Shiying Fan ◽

Zhifan Yin ◽

...

Keyword(s):

Low Temperature ◽

Nh3 Scr ◽

So2 Poisoning ◽

Removal Of Metal ◽

Insight Into

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Low temperature high activity of M (M = Ce, Fe, Co, Ni) doped M-Mn/TiO2 catalysts for NH3-SCR and in situ DRIFTS for investigating the reaction mechanism

Applied Surface Science ◽

10.1016/j.apsusc.2020.146014 ◽

2020 ◽

Vol 515 ◽

pp. 146014 ◽

Cited By ~ 5

Author(s):

Shangzhi Xie ◽

Lulu Li ◽

Lijian Jin ◽

Yaohui Wu ◽

Hao Liu ◽

...

Keyword(s):

Reaction Mechanism ◽

Low Temperature ◽

High Activity ◽

In Situ Drifts ◽

Nh3 Scr

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In Situ DRIFTS Investigation on CeOx Catalyst Supported by Fly-Ash-Made Porous Cordierite Ceramics for Low-Temperature NH3-SCR of NOX

Catalysts ◽

10.3390/catal9060496 ◽

2019 ◽

Vol 9 (6) ◽

pp. 496 ◽

Cited By ~ 4

Author(s):

Shaoxin Wang ◽

Ziwei Chen ◽

Beini He ◽

Zheng Yan ◽

Hao Wang ◽

...

Keyword(s):

Fly Ash ◽

Low Temperature ◽

Photoelectron Spectroscopy ◽

Active Sites ◽

Supported Catalyst ◽

Nh3 Scr ◽

Scr Catalysts ◽

Cordierite Ceramics ◽

Porous Cordierite

A series of CeOx catalysts supported by commercial porous cordierite ceramics (CPCC) and synthesized porous cordierite ceramics (SPCC) from fly ash were prepared for selective catalytic reduction of NOx with ammonia (NH3-SCR). A greater than 90% NOx conversion rate was achieved by the SPCC supported catalyst at 250–300 °C when the concentration of loading precursor was 0.6 mol/L (denoted as 0.6Ce/SPCC), which is more advantageous than the CPCC supported ones. The EDS mapping results reveal the existence of evenly distributed impurities on the surface of SPCC, which hence might be able to provide more attachment sites for CeOx particles. Further measurements with temperature programmed reduction by hydrogen (H2-TPR) demonstrate more reducible species on the surface of 0.6Ce/SPCC, thus giving rise to better NH3-SCR performance at a low-temperature range. The X-ray photoelectron spectroscopy (XPS) analyses reveal that the Ce atom ratio is higher in 0.6Ce/SPCC, indicating that a higher concentration of catalytic active sites could be found on the surface of 0.6Ce/SPCC. The in situ diffused reflectance infrared fourier transform spectroscopy (DRIFTS) results indicate that the SCR reactions over 0.6Ce/SPCC follow both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. Hence, the SPCC might be a promising candidate to provide support for NH3-SCR catalysts, which also provide a valuable approach to recycling the fly ash.

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Accelerated identification of high-performance catalysts for low-temperature NH3-SCR by machine learning

Journal of Materials Chemistry A ◽

10.1039/d1ta06772a ◽

2021 ◽

Author(s):

Yi Dong ◽

Yu Zhang ◽

Mingchu Ran ◽

Xiao Zhang ◽

Shaojun Liu ◽

...

Keyword(s):

Machine Learning ◽

Low Temperature ◽

High Performance ◽

Rapid Screening ◽

Learning Approach ◽

Scr Catalyst ◽

Nh3 Scr ◽

Machine Learning Approach

A machine learning approach for SCR catalyst discovery is presented to realize the rapid screening of optimal catalysts.

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In situ formed graphene/ZnO nanostructured composites for low temperature hydrogen sulfide removal from natural gas

RSC Advances ◽

10.1039/c6ra08763a ◽

2016 ◽

Vol 6 (84) ◽

pp. 81142-81150 ◽

Cited By ~ 16

Author(s):

Sunil P. Lonkar ◽

Vishnu Pillai ◽

Ahmed Abdala ◽

Vikas Mittal

Keyword(s):

Hydrogen Sulfide ◽

Low Temperature ◽

Zno Nanoparticles ◽

Freeze Drying ◽

Nanostructured Composites ◽

Hydrogen Sulfide Removal ◽

Highly Dispersed ◽

Novel Method ◽

20 Nm

Nanostructured composites of graphene and highly dispersed sub-20 nm sized ZnO nanoparticles (TRGZ) were prepared via a novel method combining freeze-drying and thermal annealing.

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Modification of V2O5-WO3/TiO2 Catalyst by Loading of MnOx for Enhanced Low-Temperature NH3-SCR Performance

Nanomaterials ◽

10.3390/nano10101900 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1900

Author(s):

Xianlong Zhang ◽

Qinchao Diao ◽

Xiaorui Hu ◽

Xueping Wu ◽

Kesong Xiao ◽

...

Keyword(s):

Manganese Oxides ◽

Catalytic Reduction ◽

In Situ Growth ◽

X Ray Diffraction ◽

Scr Catalyst ◽

X Ray ◽

Nh3 Scr ◽

Growth Method ◽

Temperature Programmed

V2O5-WO3/TiO2 as a commercial selective catalytic reduction (SCR) catalyst usually used at middle-high temperatures was modified by loading of MnOx for the purpose of enhancing its performance at lower temperatures. Manganese oxides were loaded onto V-W/Ti monolith by the methods of impregnation (I), precipitation (P), and in-situ growth (S), respectively. SCR activity of each modified catalyst was investigated at temperatures in the range of 100–340 °C. Catalysts were characterized by specific surface area and pore size determination (BET), X-ray diffraction (XRD), temperature programmed reduction (TPR), etc. Results show that the loading of MnOx remarkably enhanced the SCR activity at a temperature lower than 280 °C. The catalyst prepared by the in-situ growth method was found to be most active for SCR.

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