Influence of elevated surface texture hydrated titania on Ce-doped Mn/TiO2 catalysts for the low-temperature SCR of NO  under oxygen-rich conditions

Boningari, Thirupathi; Ettireddy, Padmanabha R.; Somogyvari, A.; Liu, Yi; Vorontsov, Alexander V.; McDonald, Carl A.; Smirniotis, Panagiotis G.

doi:10.1016/j.jcat.2015.03.002

Cited by 431 publications

(192 citation statements)

References 46 publications

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“…Figure 2A Figure S1), and XRD (Supporting Information Figure S2 36 The more is Ce 31 , the easier form oxygen vacancies, and the more advantageous is the adsorption of oxygen on catalyst surface to form chemisorbed oxygen species. It is favorable for the oxidation of NO to NO 2 , and thus facilitates the improvement of the NH 3 -SCR performance at the low-temperature.…”

Section: Resultsmentioning

confidence: 99%

Fe‐Beta@CeO₂ core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NO_x with NH₃

Liu

Zhao

et al. 2017

AIChE Journal

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A series of core-shell structural deNO x catalysts using small-grain Beta supporting FeO x nanoparticles as the core and tunable CeO 2 thin film thickness as sheaths were designed and controllably synthesized. Their catalytic performances were tested for selective catalytic reduction of NO x with NH 3 (NH 3 -SCR). It was found that CeO 2 shell thickness plays an important role in influencing the acidity and redox properties of the catalysts. Fe-Beta@CeO 2 core-shell catalysts exhibit excellent resistance to H 2 O and SO 2 and high NO x conversion (above 90%) in the wide temperature range (225-5658C). The kinetics result indicates that the coating of CeO 2 shell significantly increases the pore diffusion resistance of Fe-Beta@CeO 2 catalysts. Furthermore, in situ DRIFT results reveal that CeO 2 shell can promote the formation of NO 2 and cis-N 2 O 2 2 species. But too thick CeO 2 shell ($20 nm) would result in the formation of inactive nitrate species, and thereby lead to a decrease of high-temperature activity of the catalysts.

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Section: Resultsmentioning

confidence: 99%

Fe‐Beta@CeO₂ core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NO_x with NH₃

Liu

Zhao

et al. 2017

AIChE Journal

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“…It has been widely reported that oxygen in the gas phase can be activated by oxygen vacancies on the surface of SCR catalysts. Therefore, the relative abundance of O ads is of particular interest because an increased percentage of O ads can promote the oxidation of NO to NO 2 , and enhance the SCR performance at low temperature through a rapid NH 3 -SCR route [49,50]. As shown in Table 2, the ratio of O ads /O total on the surface of the MnO x -Fe 2 O 3 /VMT catalyst is about 19% greater than that for the MnO x /VMT catalyst.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Low Temperature NO Reduction Performance via MnOx-Fe2O3/Vermiculite Monolithic Honeycomb Catalysts

Zhang

Dan

et al. 2018

Catalysts

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Selective catalytic reduction of NO x by ammonia (NH 3 -SCR) was the most efficient and economic technology for De-NO x applications. Therefore, a series of MnO x /vermiculite (VMT) and MnO x -Fe 2 O 3 /VMT catalysts were prepared by an impregnation method for the selective catalytic reduction (SCR) of nitrogen oxides (NO x ). The MnO x -Fe 2 O 3 /VMT catalysts provided an excellent NO conversion of 96.5% at 200 • C with a gas hourly space velocity (GHSV) of 30,000 h −1 and an NO concentration of 500 ppm. X-ray photoelectron spectroscopy results indicated that the Mn and Fe oxides of the MnO x -Fe 2 O 3 /VMT catalyst were mainly composed of MnO 2 and Fe 2 O 3 . However, the MnO 2 and Fe 2 O 3 components were well dispersed because no discernible MnO 2 and Fe 2 O 3 phases were observed in X-ray powder diffraction spectra. Corresponding MnO x -Fe 2 O 3 /VMT monolithic honeycomb catalysts (MHCs) were prepared by an extrusion method, and the MHCs achieved excellent SCR activity at low temperature, with an NO conversion greater than 98.6% at 150 • C and a GHSV of 4000 h −1 . In particular, the MnO x -Fe 2 O 3 /VMT MHCs provided a good SCR activity at room temperature (20 • C), with an NO conversion of 62.2% (GHSV = 1000 h −1 ). In addition, the NO reduction performance of the MnO x -Fe 2 O 3 /VMT MHCs also demonstrated an excellent SO 2 resistance.

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“…It is known that HPAs have stronger (Brönsted) acidity, but it was reported that (NH 4 ) 3 PMo 12 O 40 provides Lewis acid sites that were strong at high temperature because of the oxygen-deficient Keggin structure [22]. The NH 3 -desorption peaks in the temperature programmed desorption of ammonia (NH 3 -TPD) was interconnected to the concentration of acid sites [23]. Combined with the results for NH 3 -TPD ( Figure S3), the peak area of Cat-A was more than Cat-B, which suggested that the concentration of Lewis acid sites was more than Cat-B.…”

Section: Catalytic Activitymentioning

confidence: 99%

DRIFT Study on Promotion Effect of the Keggin Structure over V2O5-MoO3/TiO2 Catalysts for Low Temperature NH3-SCR Reaction

Zhang

et al. 2018

Catalysts

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Abstract:Heteropoly acids (HPAs) with the Keggin structure have been widely used in NO x removal. Two kinds of catalysts (those with and without the Keggin structure) are prepared for studying the effect of the Keggin structure on the NH 3 -SCR reaction. A series of in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) analyses are conducted to investigate the surface-adsorbed species on the catalysts during the SCR reaction. The mechanism for enhancing low-temperature activity of the catalysts is proposed. Furthermore, the effect of NH 4 + in the Keggin structure is also investigated. Results indicate that both the Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms occurred in the NH 3 -SCR reaction over the catalyst with the Keggin structure (Cat-A); in addition, when more acid sites are provided, NO x species activity is improved and more NH 4 + ions participate in reaction over Cat-A, thus promoting SCR activity.

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Influence of elevated surface texture hydrated titania on Ce-doped Mn/TiO2 catalysts for the low-temperature SCR of NO under oxygen-rich conditions

Cited by 431 publications

References 46 publications

Fe‐Beta@CeO₂ core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NO_x with NH₃

Fe‐Beta@CeO₂ core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NO_x with NH₃

Enhanced Low Temperature NO Reduction Performance via MnOx-Fe2O3/Vermiculite Monolithic Honeycomb Catalysts

DRIFT Study on Promotion Effect of the Keggin Structure over V2O5-MoO3/TiO2 Catalysts for Low Temperature NH3-SCR Reaction

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Influence of elevated surface texture hydrated titania on Ce-doped Mn/TiO2 catalysts for the low-temperature SCR of NO under oxygen-rich conditions

Cited by 431 publications

References 46 publications

Fe‐Beta@CeO2 core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NOx with NH3

Fe‐Beta@CeO2 core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NOx with NH3

Enhanced Low Temperature NO Reduction Performance via MnOx-Fe2O3/Vermiculite Monolithic Honeycomb Catalysts

DRIFT Study on Promotion Effect of the Keggin Structure over V2O5-MoO3/TiO2 Catalysts for Low Temperature NH3-SCR Reaction

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Product

Resources

About

Fe‐Beta@CeO₂ core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NO_x with NH₃

Fe‐Beta@CeO₂ core‐shell catalyst with tunable shell thickness for selective catalytic reduction of NO_x with NH₃