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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Applications of Zeolites to C1 Chemistry: Recent Advances, Challenges, and Opportunities

Advanced Materials, Journal Year: 2020, Volume and Issue: 32(44)

Published: July 22, 2020

Abstract C1 chemistry, which is the catalytic transformation of molecules including CO, CO 2 , CH 4 3 OH, and HCOOH, plays an important role in providing energy chemical supplies while meeting environmental requirements. Zeolites are highly efficient solid catalysts used industry. The design development zeolite‐based mono‐, bi‐, multifunctional has led to a booming application chemistry. Combining advantages zeolites metallic species promoted production various hydrocarbons (e.g., methane, light olefins, aromatics, liquid fuels) oxygenates methanol, dimethyl ether, formic acid, higher alcohols) from molecules. key zeolite descriptors that influence performance, such as framework topologies, nanoconfinement effects, Brønsted acidities, secondary‐pore systems, particle sizes, extraframework cations atoms, hydrophobicity hydrophilicity, proximity between acid sites discussed provide deep understanding significance An outlook regarding challenges opportunities for conversion resources using meet emerging demands also presented.

Language: Английский

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Continuous Partial Oxidation of Methane to Methanol Catalyzed by Diffusion-Paired Copper Dimers in Copper-Exchanged Zeolites

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(29), P. 11641 - 11650

Published: June 21, 2019

Copper-exchanged zeolites can continuously and selectively catalyze the partial oxidation of methane to methanol using only oxygen water at low temperatures, but genesis nature active sites are currently unknown. Herein, we demonstrate that this reaction is catalyzed by a [Cu–O–Cu]2+ motif forms via hypothesized proton-aided diffusion hydrated Cu ions within cages SSZ-13 zeolites. While various configurations may be present for oxidation, dimeric primary site selective oxidation. Mechanistically, CH4 activation proceeds rate-determining C–H scission form surface-bound C1 intermediate either desorbed as in presence H2O/H+ or completely oxidized CO2 gas-phase O2. High selectivity obtained with (i) high pressures (ii) maximizing dimer formation Al content loadings.

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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Activation and conversion of alkanes in the confined space of zeolite-type materials

Chemical Society Reviews, Journal Year: 2021, Volume and Issue: 50(15), P. 8511 - 8595

Published: Jan. 1, 2021

Microporous zeolite-type materials are able to activate and efficiently convert stable C₁⁺alkanes. This review analyzes, at the molecular level, role of active sites contribution diffusion, shape-selectivity confinement effects.

Language: Английский

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Cu-Based Nanocatalysts for CO₂ Hydrogenation to Methanol

Energy & Fuels, Journal Year: 2021, Volume and Issue: 35(10), P. 8558 - 8584

Published: May 5, 2021

Production of methanol from CO2 hydrogenation is a highly attractive method toward recycling greenhouse gases to form clean, high-value commodity chemicals and fuels, with the aim resolving both environmental issues energy shortages. This review provides an overview Cu-based nanocatalyst development for that has been achieved recently in terms support design, promoter addition, structural improvements, as this line research become very popular. In reaction mechanisms experimental work density functional theory calculations are summarized showcase key factors influencing reaction. The overall yield can be tailored by metal active sites metal–support interaction, well function promoters. technical application challenges production also proposed future directions.

Language: Английский

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Research progress on methane conversion coupling photocatalysis and thermocatalysis

Carbon Energy, Journal Year: 2021, Volume and Issue: 3(4), P. 519 - 540

Published: July 22, 2021

Abstract Conversion of methane into value‐added chemicals is significance for utilization and industrial demand primary chemical products. The barrier associated with the nonpolar structure high bond energy C–H (4.57 eV) makes it difficult to realize conversion activation under mild conditions. photothermal synergetic strategy by combining photon thermo provides an advanced philosophy achieve efficient conversion. In this review, we overview current pioneering studies indirect present direct way photocatalysis thermocatalysis provide a fundamental understanding activation. Finally, end review discussion on remaining challenges perspectives over single‐atom catalysts via strategy.

Language: Английский

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Single Atom Catalysts for Selective Methane Oxidation to Oxygenates

ACS Nano, Journal Year: 2022, Volume and Issue: 16(6), P. 8557 - 8618

Published: May 31, 2022

Direct conversion of methane (CH4) to C1–2 liquid oxygenates is a captivating approach lock carbons in transportable value-added chemicals, while reducing global warming. Existing approaches utilizing the transformation CH4 fuel via tandemized steam reforming and Fischer–Tropsch synthesis are energy capital intensive. Chemocatalytic partial oxidation remains challenging due negligible electron affinity, poor C–H bond polarizability, high activation barrier. Transition-metal stoichiometric catalysts harsh oxidants reaction conditions perform poorly with randomized product distribution. Paradoxically, which active enough break also promote overoxidation, resulting CO2 generation reduced carbon balance. Developing can bonds selectively make useful chemicals at mild vital commercialization. Single atom (SACs) specifically coordinated metal centers on support have displayed intrigued reactivity selectivity for oxidation. SACs significantly reduce induced electrostatic polarization facilitate accelerated rate low temperature. The distinct metal–support interaction stabilize intermediate prevent overoxidation products. present review accounts recent progress field selective oxygenates. chemical nature catalytic sites, effects interaction, stabilization species minimize thoroughly discussed forward-looking perspective improve performance.

Language: Английский

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First-Generation Organic Reaction Intermediates in Zeolite Chemistry and Catalysis

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(18), P. 14275 - 14345

Published: Aug. 10, 2022

Zeolite chemistry and catalysis are expected to play a decisive role in the next decade(s) build more decentralized renewable feedstock-dependent sustainable society owing increased scrutiny over carbon emissions. Therefore, lack of fundamental mechanistic understanding these processes is critical "technical bottleneck" that must be eliminated maximize economic value minimize waste. We have identified, considering this objective, related first-generation reaction intermediates (i.e., carbocations, radicals, carbenes, ketenes, carbanions) zeolite highly underdeveloped or undervalued compared other streams (e.g., homogeneous catalysis). This limitation can often attributed technological restrictions detect such "short-lived reactive" at interface (gas-solid/solid-liquid); however, recent rise sophisticated spectroscopic/analytical techniques (including under situ/operando conditions) modern data analysis methods collectively compete unravel impact organic intermediates. comprehensive review summarizes state-of-the-art evaluates their existing challenges future prospects, contribute significantly "circular economy" initiatives.

Language: Английский

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Metal–organic frameworks as catalysts and biocatalysts for methane oxidation: The current state of the art

Coordination Chemistry Reviews, Journal Year: 2023, Volume and Issue: 481, P. 215042 - 215042

Published: Feb. 9, 2023

Language: Английский

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