Excellent low-temperature NH3-SCR of NO activity and resistance to H2O and SO2 over WaCeOx (a = 0.06, 0.12, 0.18, 0.24) catalysts: Key role of acidity derived from tungsten addition

Tan, Huansheng; Ma, Shibo; Zhao, Xiaoyu; Li, Yushi; Zhao, Chen; Zhu, Yujun

doi:10.1016/j.apcata.2021.118374

Cited by 24 publications

(3 citation statements)

References 67 publications

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“…An additional band is observed at 3215 cm –1 in the N–H stretching region related to the NH 3 or NH 4 + species (Table S7). In the N–H bending region, there is a band at 1610 cm –1 , and an additional band at 1729 cm –1 , probably attributed to NH 4 + on Bro̷nsted acid sites (BAS). , Furthermore, two bands displaying negative features linked to O–H stretching at 3730 and 3657 cm –1 that were absent in the case of Mn/MesoTS-1 catalyst could be linked to the interaction of NH 3 with hydroxyl groups. − Based on the NH 3 -adsorption DRIFTS study, additional acid sites are appearing in Mn/MesoTS-1@S1 that contribute to the adsorption of more NH x species.…”

Section: Resultsmentioning

confidence: 99%

Enhancing Water Tolerance and N₂ Selectivity in NH₃–SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer

Komaty,

Andijani,

Wang

et al. 2024

Environ. Sci. Technol.

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Mn-based catalysts are promising candidates for eliminating harmful nitrogen oxides (NO x ) via selective catalytic reduction with ammonia (NH 3 −SCR) due to their inherent strong redox abilities. However, poor water tolerance and low N 2 selectivity are still the main limitations for practical applications. Herein, we succeeded in preparing an active catalyst for NH 3 − SCR with improved water tolerance and N 2 selectivity based on protecting MnO x with a secondary growth of a hydrophobic silicalite-1. This protection suppressed catalyst deactivation by water adsorption. Interestingly, impregnating MnO x on MesoTS-1 followed by silicalite-1 protection allowed for a higher dispersion of MnO x species, thus increasing the concentration of acid sites. Consequently, the level of N 2 O formation is decreased. These improvements resulted in a broader operating temperature of NO x conversion and a modification of the NH 3 −SCR mechanism. Diffuse reflectance infrared Fourier transform spectroscopy analysis revealed that unprotected Mn/MesoTS-1 mainly followed the Eley−Rideal mechanism, while Mn/MesoTS-1@S1 followed both Langmuir−Hinshelwood and Eley−Rideal mechanisms.

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Section: Resultsmentioning

confidence: 99%

Enhancing Water Tolerance and N₂ Selectivity in NH₃–SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer

Komaty,

Andijani,

Wang

et al. 2024

Environ. Sci. Technol.

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“…The concentration of NO x was measured by an electrochemical gas analyzer (Cairn-May Quintox Flue Gas Analyzer). The NO x conversion and N 2 selectivity were calculated using eqs and , respectively: …”

Section: Methodsmentioning

confidence: 99%

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO_x by NH₃ over MnCeO_x Catalysts: The Promotion Effect and Mechanism

Yang

Zhang

et al. 2022

ACS Omega

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A MnCeInO x catalyst was prepared by a coprecipitation method for denitrification of NH3-SCR (selective catalytic reduction). The catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis, H2 temperature-programmed reduction, and NH3 temperature-programmed desorption. The NH3-SCR activity and H2O and SO2 resistance of the catalysts were evaluated. The test results showed that the SCR and water resistance and sulfur resistance were good in the range of 125–225 °C. The calcination temperature of the Mn6Ce0.3In0.7O x catalyst preparation was studied. The crystallization of the Mn6Ce0.3In0.7O x catalyst was poor when calcined at 300 °C; however, the crystallization is excessive at a 500 °C calcination temperature. The influence of space velocity on the performance of the catalyst is great at 100–225 °C. FTIR test results showed that indium distribution on the surface of the catalyst reduced the content of sulfate on the surface, protected the acidic site of MnCe, and improved the sulfur resistance of the catalyst. The excellent performance of the Mn6Ce0.3In0.7O x catalyst may be due to its high content of Mn4+, surface adsorbed oxygen species, high specific surface area, redox sites and acid sites on the surface, high turnover frequency, and low apparent activation energy.

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“…Wang et al [109] prepared WO 3 /CeO 2 catalysts, which exhibited excellent SCR performance due to the strong interaction between W and Ce. It was also reported that W-Ce composite metal-oxide catalysts loaded with different W/Ce content were prepared via a coprecipitation method, which had a significant impact on the surface acidity, especially the number of Brønsted acid sites, with W 0.18 CeO x exhibiting the best NH 3 -SCR performance at 190-490 • C for 100% NO x conversion, while still maintaining a wide active temperature window from 235 to 460 • C when treated with 5% H 2 O at high temperature for 12 h [110]. Yao et al [111] developed TiO 2 /CeO 2 nanocubes and nanorods for the effective reduction of NO x .…”

Section: Ce-based Catalystmentioning

confidence: 99%

Research Progress on Metal Oxides for the Selective Catalytic Reduction of NOx with Ammonia

et al. 2023

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Nitrogen oxides emitted from diesel vehicle exhaust seriously endanger the atmospheric environment and human health, which have attracted people’s attention. Among numerous nitrogen oxide (NOx) removal technologies, photocatalytic removal of NOx and SCR have received widespread attention. The photocatalytic treatment of NOx technology is a good choice due to its mild reaction conditions and low costs. Moreover, NH3-SCR has been widely used in denitration technology and plays an important role in controlling NOx emissions. In NH3-SCR technology, the development of high-efficiency catalysts is an important part. This paper summarizes the research progress of metal oxide catalysts for NH3-SCR reactions, including V-based catalysts, Mn-based catalysts, Fe-based catalysts, Ce-based catalysts, and Cu-based catalysts. Meanwhile, the detailed process of the NH3-SCR reaction was also introduced. In addition, this paper also describes a possible SO2 poisoning mechanism and the stability of the catalysts. Finally, the problems and prospects of metal oxide catalysts for NOx removal were also proposed.

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Excellent low-temperature NH3-SCR of NO activity and resistance to H2O and SO2 over WaCeOx (a = 0.06, 0.12, 0.18, 0.24) catalysts: Key role of acidity derived from tungsten addition

Cited by 24 publications

References 67 publications

Enhancing Water Tolerance and N₂ Selectivity in NH₃–SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer

Enhancing Water Tolerance and N₂ Selectivity in NH₃–SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO_x by NH₃ over MnCeO_x Catalysts: The Promotion Effect and Mechanism

Research Progress on Metal Oxides for the Selective Catalytic Reduction of NOx with Ammonia

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Excellent low-temperature NH3-SCR of NO activity and resistance to H2O and SO2 over WaCeOx (a = 0.06, 0.12, 0.18, 0.24) catalysts: Key role of acidity derived from tungsten addition

Cited by 24 publications

References 67 publications

Enhancing Water Tolerance and N2 Selectivity in NH3–SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer

Enhancing Water Tolerance and N2 Selectivity in NH3–SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NOx by NH3 over MnCeOx Catalysts: The Promotion Effect and Mechanism

Research Progress on Metal Oxides for the Selective Catalytic Reduction of NOx with Ammonia

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Product

Resources

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Enhancing Water Tolerance and N₂ Selectivity in NH₃–SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer

Enhancing Water Tolerance and N₂ Selectivity in NH₃–SCR Catalysts by Protecting Mn Oxide Nanoparticles in a Silicalite-1 Layer

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO_x by NH₃ over MnCeO_x Catalysts: The Promotion Effect and Mechanism