Cu docking-activated Nb incorporation in multivariate CuO-Nb2O5/CeO2 catalysts for selective reduction of NOx with NH3

Hao, Yanheng; Wang, Yan; Zhang, Tiantian; Liu, Yang; Fan, Qi-Yuan; Jiang, Yue; Gao, Yonghui; Mao, Zhihui; Gu, Xiaojun; Zeng, Shanghong

doi:10.1016/j.apcatb.2023.123254

Cited by 18 publications

(4 citation statements)

References 85 publications

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“…The chemical state of the Ce 3d orbital in all samples was investigated by XPS, as shown in Figure c. The prominent peaks of Ce 3d 3/2 ( u ′, u ″, and u ″′) and Ce 3d 5/2 ( v ′, v ″, and v ″′) are attributed to Ce 4+ , and the other peaks ( u 0 , u , and v 0 , v ) are attributed to Ce 3+ . As can be seen from Table S4, the Ce 3+ ratio of the Ru 1 N 2 O 1 /CeO 2 catalyst increases with the loading of Ru.…”

Section: Resultsmentioning

confidence: 97%

“…The prominent peaks of Ce 3d 3/2 (u′, u″, and u″′) and Ce 3d 5/2 (v′, v″, and v″′) are attributed to Ce 4+ , and the other peaks (u 0 , u, and v 0 , v) are attributed to Ce 3+ . 31 As can be seen from Table S4, the Ce 3+ ratio of the Ru 1 N 2 O 1 /CeO 2 catalyst increases with the loading of Ru. Ce 3+ is widely recognized as an indicator of oxygen vacancies in CeO 2 , where the two electrons left after the formation of oxygen vacancies reduced Ce 4+ to Ce 3+ .…”

Section: Surface Electronic State and Characterizationmentioning

confidence: 83%

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Asymmetric Coordination of Single-Atom Ru Sites Achieves Efficient N(sp³)–H Dehydrogenation Catalysis for Ammonia Oxidation

Liu,

Xu,

Fan

et al. 2024

Environ. Sci. Technol.

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Ruthenium single-atom catalysts have great potential in ammonia-selective catalytic oxidation (NH 3 −SCO); however, the stable sp 3 hybrid orbital of NH 3 molecules makes N(sp 3 )−H dissociation a challenge for conventional symmetrical metallic oxide catalysts. Herein, we propose a heterogeneous interface reverse atom capture strategy to construct Ru with unique asymmetric Ru 1 N 2 O 1 coordination. Ru 1 N 2 O 1 /CeO 2 exhibits intrinsic low-temperature conversion (T 100 at 160 °C) compared to symmetric coordinated Ru-based (280 °C), Ir-based (220 °C), and Pt-based (200 °C) catalysts, and the TOF is 65.4 times that of Ag-based catalysts. The experimental and theoretical studies show that there is a strong d−p orbital interaction between Ru and N atoms, which not only enhances the adsorption of ammonia at the Ru 1 N 2 O 1 position but also optimizes the electronic configuration of Ru. Furthermore, the affinity of Ru 1 N 2 O 1 /CeO 2 to water is significantly weaker than that of conventional catalysts (the binding energy of the Pd 3 Au 1 catalyst is −1.19 eV, but it is −0.39 eV for our material), so it has excellent water resistance. Finally, the N(sp 3 )−H activation of NH 3 requires the assistance of surface reactive oxygen species, but we found that asymmetric Ru 1 N 2 O 1 can directly activate the N(sp 3 )−H bond without the involvement of surface reactive oxygen species. This study provides a novel principle for the rational design of the proximal coordination of active sites to achieve its optimal catalytic activity in single-atom catalysis.

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Section: Resultsmentioning

confidence: 97%

Section: Surface Electronic State and Characterizationmentioning

confidence: 83%

Asymmetric Coordination of Single-Atom Ru Sites Achieves Efficient N(sp³)–H Dehydrogenation Catalysis for Ammonia Oxidation

Liu,

Xu,

Fan

et al. 2024

Environ. Sci. Technol.

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show abstract

“…It was shown that the introduction of Al could modulate the electronic structure of the O 2p states and enhance the Lewis acid sites and lattice oxygen ability, thus promoting the adsorption and activation of NH 3 . In addition, there are also cases where the catalytic activity of CeO 2 catalysts has been obviously enhanced by Ti doping and Cu and Nb doping . The above studies indicate that suitable modification methods can significantly improve the ability of the CeO 2 catalyst to catalyze the NH 3 -SCR reaction.…”

Section: Introductionmentioning

confidence: 90%

Hexavalent Metal Cations Doped into Ceria Inducing the Formation of Binuclear Sites Ce³⁺–O–Ce³⁺ to Boost the NH₃-SCR Reaction

Yang,

Zhu,

Chen

et al. 2024

ACS Catal.

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The application of selective catalytic reduction with ammonia (NH 3 -SCR) technology urgently requires catalysts with good performance to control nitrogen oxide (NO x , x = 1, 2) emissions, and structural analysis of such catalysts is necessary and crucial to elucidate the performance of catalytically active sites. Thus, we prepared molybdenum (Mo)-doped CeO 2 catalysts to achieve a substantial leap in catalytic performance. The results revealed that the emergence of Ce 3+ −O−Ce 3+ structural units induced by Mo doping achieved the low-energy barrier activation of the NH 3 molecule, which transformed the dominant reaction mechanism in the catalytic reaction and thus led to a much better SCR performance. Furthermore, we designed tungsten (W)-doped CeO 2 catalysts with the same doping amount as Mo and found that the catalysts exhibited almost the same activity trend as the Mo-doped CeO 2 catalysts, which further confirmed the pivotal role of the Ce 3+ −O−Ce 3+ structural units. This study provides a basic theoretical foundation for the design of ceria-based SCR catalysts with efficient catalytic performance for NO x removal.

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“…NH 3 species were depleted after 3 min, bands of bidentate nitrates (1573, 1376, and 1243 cm −1 ), 48,49,53 monodentate nitrate (1533 cm −1 ), 54 and N 2 O 2 2− (1365 cm −1 ) 55 appeared, and NH 4 + species were not fully consumed until 9 min. For 12HPW-CeO 2 (Figure 4B), L-NH 3 (1600,1550,1346 and 1197 cm −1 ) 48,56 and B-NH 4 + (1724, 1660, and 1430 cm −1 ) 57−59 were observed after 30 min of preadsorption of NH 3 . When NO and O 2 were introduced for 3 min, the NH 3 species and NH 4 + species were completely consumed and monodentate nitrites (1606 and 1274 cm −1 ), 60,61 monodentate nitrate (1517 cm −1 ), 58 and bridged nitrate (1238 cm −1 ) 62 appeared, which have been increasing with time, and N 2 O 4 species (1680 cm −1 ) 62 also appeared but have been decreasing with time.…”

Section: Reaction Mechanismmentioning

confidence: 96%

Phosphotungstic Acid as a Dechlorination Agent Collaborates with CeO₂ for Synergistic Catalytic Elimination of NO_x and Chlorobenzene

Yang,

Chen,

Wang

et al. 2024

Environ. Sci. Technol.

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The development of efficient technologies for the synergistic catalytic elimination of NO x and chlorinated volatile organic compounds (CVOCs) remains challenging. Chlorine species from CVOCs are prone to catalyst poisoning, which increases the degradation temperature of CVOCs and fails to balance the selective catalytic reduction of NO x with the NH 3 (NH 3 −SCR) performance. Herein, synergistic catalytic elimination of NO x and chlorobenzene has been originally demonstrated by using phosphotungstic acid (HPW) as a dechlorination agent to collaborate with CeO 2 . The conversion of chlorobenzene was over 80% at 270 °C, and the NO x conversion and N 2 selectivity reached over 95% at 270−420 °C. HPW not only allowed chlorine species to leave as inorganic chlorine but also enhanced the Bro̷ nsted acidity of CeO 2 . The NH 4 + produced in the NH 3 −SCR process can effectively promote the dechlorination of chlorobenzene at low temperatures. HPW remained structurally stable in the synergistic reaction, resulting in good water resistance and long-term stability. This work provides a cheaper and more environmentally friendly strategy to address chlorine poisoning in the synergistic reaction and offers new guidance for multipollutant control.

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Cu docking-activated Nb incorporation in multivariate CuO-Nb2O5/CeO2 catalysts for selective reduction of NOx with NH3

Cited by 18 publications

References 85 publications

Asymmetric Coordination of Single-Atom Ru Sites Achieves Efficient N(sp³)–H Dehydrogenation Catalysis for Ammonia Oxidation

Asymmetric Coordination of Single-Atom Ru Sites Achieves Efficient N(sp³)–H Dehydrogenation Catalysis for Ammonia Oxidation

Hexavalent Metal Cations Doped into Ceria Inducing the Formation of Binuclear Sites Ce³⁺–O–Ce³⁺ to Boost the NH₃-SCR Reaction

Phosphotungstic Acid as a Dechlorination Agent Collaborates with CeO₂ for Synergistic Catalytic Elimination of NO_x and Chlorobenzene

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Cu docking-activated Nb incorporation in multivariate CuO-Nb2O5/CeO2 catalysts for selective reduction of NOx with NH3

Cited by 18 publications

References 85 publications

Asymmetric Coordination of Single-Atom Ru Sites Achieves Efficient N(sp3)–H Dehydrogenation Catalysis for Ammonia Oxidation

Asymmetric Coordination of Single-Atom Ru Sites Achieves Efficient N(sp3)–H Dehydrogenation Catalysis for Ammonia Oxidation

Hexavalent Metal Cations Doped into Ceria Inducing the Formation of Binuclear Sites Ce3+–O–Ce3+ to Boost the NH3-SCR Reaction

Phosphotungstic Acid as a Dechlorination Agent Collaborates with CeO2 for Synergistic Catalytic Elimination of NOx and Chlorobenzene

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Asymmetric Coordination of Single-Atom Ru Sites Achieves Efficient N(sp³)–H Dehydrogenation Catalysis for Ammonia Oxidation

Asymmetric Coordination of Single-Atom Ru Sites Achieves Efficient N(sp³)–H Dehydrogenation Catalysis for Ammonia Oxidation

Hexavalent Metal Cations Doped into Ceria Inducing the Formation of Binuclear Sites Ce³⁺–O–Ce³⁺ to Boost the NH₃-SCR Reaction

Phosphotungstic Acid as a Dechlorination Agent Collaborates with CeO₂ for Synergistic Catalytic Elimination of NO_x and Chlorobenzene