d-π Orbital Interaction Promoting NO_x Selective Reduction on the Mn-Doped α-Fe₂O₃(001) Catalyst

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 18, 2025

Understanding the structure–activity relationship on a solid surface is crucial for developing an efficient low-temperature NH3–SCR catalyst. Herein, in-depth investigation was conducted single-atom Mn-doped α-Fe2O3 catalyst by combining experimental studies and density functional theory calculations. Mn doping not only facilitates N–H cleavage in Eley–Rideal (E–R) pathway but also promotes adsorption of NO N–O bond, lowering energy barrier rate-determining step Langmuir–Hinshelwood (L–H) pathway. Thus, catalytic reaction along both potential pathways, which reaction. Further analysis reveals that introduces unoccupied dxy orbital, interaction with π orbital NO, thereby augmenting adsorption. Moreover, redistributes electron density, enhancing flexibility electrons Fe atom facilitating transfer from to π* Mn–N–O, thus promoting cleavage. The present study demonstrates incorporation d orbitals appropriate symmetry d-π between dopant reactant, significantly efficiency. These findings provide valuable new insights into design high-performance catalysts.

Language: Английский

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Revealing the potassium poisoning mechanism of V2O5-MoO3/TiO2 catalyst for chlorobenzene catalytic oxidation

Fuel, Journal Year: 2025, Volume and Issue: 390, P. 134766 - 134766

Published: Feb. 19, 2025

Language: Английский

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Engineering Unsaturated Cu₁–O₃ Coordination to Boost Oxygen Species Activation for Low-Temperature Catalysis in CO Oxidation

JACS Au, Journal Year: 2025, Volume and Issue: unknown

Published: April 15, 2025

The activation of lattice oxygen at low temperatures is essential for heterogeneous catalytic oxidation, but exactly how this achieved by adjusting the coordination structure atomic sites still elusive. Herein, Cu1O3-CeO2 catalyst with highly dispersed unsaturated Cu1-O3 was creatively engineered, which remarkably enhanced low-temperature oxidation CO (a typical model reaction) from 12% to 90% 66 °C compared conventional CuCeO x catalyst. preservation coordination-deficient Cu enables transfer electron cloud density atoms O atoms, hence, facilitating oxygen. Further atom species results in charge back-donation form sufficient Cu+ and metal per-oxy species, contributing weaken O-O bonds. We determined that increasing number donors induced an efficient strategy develop active stable catalysts activation. synthesis strategies mechanism demonstrated work provide a generalizable platform future design well-defined functional reactions.

Language: Английский

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Unraveling the anti-poisoning mechanism of highly dispersed Ni atoms enhanced porous MnOx catalysts in the selective reduction of NOx by NH3

Journal of Colloid and Interface Science, Journal Year: 2025, Volume and Issue: unknown, P. 137662 - 137662

Published: April 1, 2025

Language: Английский

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Defect-engineered Cu O/CeO2 catalysts: Enhanced low-temperature CO preferential oxidation through dual-promotion of CO adsorption and O2 activation

Molecular Catalysis, Journal Year: 2025, Volume and Issue: 581, P. 115148 - 115148

Published: April 22, 2025

Language: Английский

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Transformation of Arsenic from Poison into Active Site by Construction of Unique AsO_x/CeO₂ Interface for Stable NO_x Removal

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 5, 2024

Arsenic in the flue gas has been widely reported as a common poison for SCR catalysts; however, an appropriate coping strategy is still lacking to improve arsenic resistance performance. Herein, unique AsOx/CeO2 interface constructed transform from into active site with balanced acid-redox property, successfully achieving efficient NOx removal. The optimized exhibits high removal efficiency, four times that of As-poisoned V2O5/TiO2 catalyst, and even comparable state-of-the-art catalysts. It was found As–O–Ce interfacial sites oxygen-bridged As dimers on CeO2 can provide both Lewis acid lattice oxygen species, enhancing adsorption activation NH3 form key –NH2 intermediates, thereby facilitating NH3–SCR reaction. More surprisingly, thin layer top capture protect catalysts attacking, which improves catalytic activity 2.8 × 10–7 mol g–1 s–1, higher than fresh (2.0 s–1). Therefore, this provides new ideas not only designing antipoisoning but also feasible solution stable operation commercial arsenic-containing gas.

Language: Английский

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Catalytic Ozonation of Low Concentration Toluene over MnFeOx-USY Catalyst: Effects of Interactions between Catalytic Components and Introduction of Gas Phase NO_x

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(32), P. 14329 - 14337

Published: Aug. 1, 2024

A series of Mn and Fe metal oxide catalysts loaded onto USY, as well single oxides, were prepared characterized. The effects interactions between the catalytic components introduction gas phase NO on ozonation toluene investigated. Characterization showed that there existed strong MnOx, FeOx, which enhanced content oxygen vacancies acid sites thus boosted generation reactive species adsorption toluene. MnFeOx-USY catalyst with MnOx FeOx dimetallic oxides exhibited most excellent performance On other hand, presence NOx in reaction mixtures significantly promoted both conversion mineralization, was attributed to formation nitrate surface increase oxidation sites. Meanwhile, mechanism O3 C7H8 modified USY accelerated progress based L-H route. In addition, not only following route but also resulted occurrence via E-R

Language: Английский

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