Metal Sites in Zeolites: Synthesis, Characterization, and Catalysis

Chemical Reviews, Journal Year: 2022, Volume and Issue: 123(9), P. 6039 - 6106

Published: Sept. 1, 2022

Zeolites with ordered microporous systems, distinct framework topologies, good spatial nanoconfinement effects, and superior (hydro)thermal stability are an ideal scaffold for planting diverse active metal species, including single sites, clusters, nanoparticles in the framework-associated sites extra-framework positions, thus affording metal-in-zeolite catalysts outstanding activity, unique shape selectivity, enhanced recyclability processes of Brønsted acid-, Lewis metal-catalyzed reactions. Especially, thanks to advances zeolite synthesis characterization techniques recent years, zeolite-confined (denoted as metal@zeolite composites) have experienced rapid development heterogeneous catalysis, owing combination merits both intrinsic properties. In this review, we will present developments strategies incorporating tailoring zeolites advanced identification location, distribution, coordination environment species zeolites. Furthermore, catalytic applications demonstrated, emphasis on composites hydrogenation, dehydrogenation, oxidation Finally, point out current challenges future perspectives precise synthesis, atomic level identification, practical application catalyst system.

Language: Английский

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Advances in Catalytic Applications of Zeolite‐Supported Metal Catalysts

Advanced Materials, Journal Year: 2021, Volume and Issue: 33(51)

Published: Oct. 5, 2021

Abstract Zeolites possessing large specific surface areas, ordered micropores, and adjustable acidity/basicity have emerged as ideal supports to immobilize metal species with small sizes high dispersities. In recent years, the zeolite‐supported catalysts been widely used in diverse catalytic processes, showing excellent activity, superior thermal/hydrothermal stability, unique shape‐selectivity. this review, a comprehensive summary of state‐of‐the‐art achievements applications are presented for important heterogeneous processes last five mainly including 1) hydrogenation reactions (e.g., CO/CO 2 hydrogenation, unsaturated compounds, nitrogenous compounds); 2) dehydrogenation alkane chemical hydrogen storage materials); 3) oxidation CO oxidation, methane alkene epoxidation); 4) other hydroisomerization reaction selective reduction NO x ammonia reaction). Finally, some current limitations future perspectives on challenge opportunity subject pointed out. It is believed that review will inspire more innovative research synthesis catalysis promote their developments meet emerging demands practical applications.

Language: Английский

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Selective catalytic reduction of NOx with NH3: opportunities and challenges of Cu-based small-pore zeolites

National Science Review, Journal Year: 2021, Volume and Issue: 8(10)

Published: Jan. 15, 2021

Abstract Zeolites, as efficient and stable catalysts, are widely used in the environmental catalysis field. Typically, Cu-SSZ-13 with small-pore structure shows excellent catalytic activity for selective reduction of NOx ammonia (NH3-SCR) well high hydrothermal stability. This review summarizes major advances applied to NH3-SCR reaction, including state copper species, standard fast SCR reaction mechanism, deactivation poisoning resistance synthetic methodology. The gives a valuable summary new insights into matching between catalyst design principles characteristics Cu2+-exchanged zeolitic highlighting significant opportunity presented by zeolite-based catalysts. Principles designing zeolites performance stability proposed. On basis these principles, more hydrothermally Cu-AEI Cu-LTA elaborated other alternative NH3-SCR. Finally, we call attention challenges facing Cu-based that still need be addressed.

Language: Английский

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On the Redox Mechanism of Low‐Temperature NH₃‐SCR over Cu‐CHA: A Combined Experimental and Theoretical Study of the Reduction Half Cycle

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(13), P. 7197 - 7204

Published: Jan. 6, 2021

Abstract Cu‐CHA is the state‐of‐the‐art catalyst for Selective Catalytic Reduction (SCR) of NOx in vehicle applications. Although extensively studied, diverse mechanistic proposals still stand terms nature active Cu‐ions and reaction pathways SCR working conditions. Herein we address redox mechanism underlying Low‐Temperature (LT) on by an integration chemical‐trapping techniques, transient‐response methods, operando UV/Vis‐NIR spectroscopy with modelling tools based transient kinetic analysis density functional theory calculations. We show that rates Half‐Cycle (RHC) LT‐SCR display a quadratic dependence Cu II , thus questioning mechanisms isolated ‐ions. propose, instead, ‐pair mediated LT‐RHC pathway, which NO oxidative activation to mobile nitrite‐precursor intermediates accounts reduction. These results highlight role dinuclear complexes not only oxidation part LT‐SCR, but also RHC cascade.

Language: Английский

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Integrating Enrichment, Reduction, and Oxidation Sites in One System for Artificial Photosynthetic Diluted CO₂ Reduction

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(40)

Published: June 26, 2023

Artificial photosynthetic diluted CO2 reduction directly driven by natural sunlight is a challenging, but promising way to realize carbon-resources recycling utilization. Herein, three-in-one photocatalytic system of enrichment, and H2 O oxidation sites designed for reduction. A Zn-Salen-based covalent organic framework (Zn-S-COF) with reductive synthesized; then, ionic liquids (ILs) are loaded into the pores. As result, [Emim]BF4 @Zn-S-COF shows visible-light-driven -to-CO conversion rate 105.88 µmol g-1 h-1 under (15%) atmosphere, even superior than most photocatalysts in high concentrations . Moreover, also reaches 126.51 5 h. Further experiments theoretical calculations reveal that triazine ring Zn-S-COF promotes activity sites, ILs provide an enriched realizing efficient

Language: Английский

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Strikingly distinctive NH3-SCR behavior over Cu-SSZ-13 in the presence of NO2

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Aug. 8, 2022

Commercial Cu-exchanged small-pore SSZ-13 (Cu-SSZ-13) zeolite catalysts are highly active for the standard selective catalytic reduction (SCR) of NO with NH

Language: Английский

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Morphology and composition dependence of multicomponent Cu-based nanoreactor for tandem electrocatalysis CO2 reduction

Applied Catalysis B Environment and Energy, Journal Year: 2022, Volume and Issue: 314, P. 121498 - 121498

Published: May 11, 2022

Language: Английский

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Influence of framework Al density in chabazite zeolites on copper ion mobility and reactivity during NOx selective catalytic reduction with NH3

Nature Catalysis, Journal Year: 2023, Volume and Issue: 6(3), P. 276 - 285

Published: March 20, 2023

Language: Английский

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Steering CO₂ Electroreduction Selectivity U-Turn to Ethylene by Cu–Si Bonded Interface

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 146(1), P. 289 - 297

Published: Dec. 22, 2023

Copper (Cu), with the advantage of producing a deep reduction product, is unique catalyst for electrochemical CO2 (CO2RR). Designing Cu-based to trigger CO2RR multicarbon product and understanding accurate structure–activity relationship elucidating reaction mechanisms still remain challenge. Herein, we demonstrate rational design core–shell structured silica-copper (p-Cu@m-SiO2) through Cu–Si direct bonding efficient selective CO2RR. The interface fulfills inversion in selectivity. ratio C2H4/CH4 changes from 0.6 14.4 after silica modification, current density reaches high up 450 mA cm–2. kinetic isotopic effect, situ attenuated total reflection Fourier-transform infrared spectra, functional theory were applied elucidate mechanism. SiO2 shell stabilizes *H intermediate by forming Si–O–H inhibits hydrogen evolution effectively. Moreover, direct-bonded makes bare Cu sites larger charge density. Such stabilized *CHO activated *CO, promoting coupling *CO intermediates form C2H4. This work provides promising strategy designing catalysts C2H4 catalytic activity.

Language: Английский

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In Situ UV–Vis–NIR Absorption Spectroscopy and Catalysis

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(5), P. 2352 - 2418

Published: Feb. 26, 2024

This review highlights

Language: Английский

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