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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Direct Methane to Methanol Conversion: An Overview of Non‐Syn Gas Catalytic Strategies

The Chemical Record, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 16, 2025

Abstract Direct methane to methanol conversion is a dream reaction in industrial chemistry, which takes inspiration from the biological production catalysed by monooxygenase enzymes (MMOs). Over years, extensive studies have been conducted on this topic bioengineering MMOs, and tailoring methods isolate MMOs active form. Similarly, remarkable achievements noted other activation strategies such as use of heterogeneous catalysts or molecular catalysts. In review, we outline metabolism performed methanotrophs detail latest advancements site structures catalytic mechanisms both types MMOs. Also, recent progress bioinspired approaches using various catalysts, especially first‐row transition metal zeolites mechanistic insights are discussed. addition, complexes “Periana catalyst” for through methyl ester formation presence strong acids also detailed. Compared zeolites‐mediated field, utilisation application still its nascent phase further research required overcome limitations these effectively.

Language: Английский

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Microenvironment Modulation for Electronic Structure of Atomically Dispersed Ir Species in Metal–Organic Frameworks Toward Boosting Catalytic DCPD Hydrogenation Performance

Carbon Neutralization, Journal Year: 2025, Volume and Issue: 4(2)

Published: March 1, 2025

ABSTRACT The fine‐tuning of the electronic structure and local environment surrounding atomically dispersed metal centers is crucial in catalysis but remains a grand challenge that requires in‐depth exploration. In this study, Ir species were incorporated into series UiO‐type metal−organic frameworks via strong metal–support interactions (SMSI), their state was precisely modulated by regulating metal‐oxo clusters (Ce, Zr, Hf) organic ligands (BDC‐X, where X = ‐H, ‐NH 2 , ‐Me, or ‐NO ) for enhancing catalytic performance dicyclopentadiene (DCPD) hydrogenation. optimized Ir@Ce‐UiO‐66‐NO effectively transforms DCPD tetrahydrodicyclopentadiene (THDCPD), giving 100% conversion over 99% THDCPD selectivity, far superior to corresponding counterparts. Experimental theoretical results jointly demonstrated Ce‐oxo with unique Ce III /Ce IV redox pairs can facilitate electron transfer species. Furthermore, electron‐withdrawing groups play role increasing ratio, promoting efficient uptake MOF support leading low density around species, which enhances stronger between substrate molecules active sites contributes excellent activity. findings presented work provide valuable insights rational design advanced heterogeneous catalysts leveraging properties modulation capabilities supports.

Language: Английский

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Selective Methane Oxidation to Acetic Acid Using Molecular Oxygen over a Mono-Copper Hydroxyl Catalyst

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(11), P. 6156 - 6165

Published: March 10, 2023

Acetic acid is an industrially important chemical, produced mainly via carbonylation of methanol using precious metal-based homogeneous catalysts. As a low-cost feedstock, methane commercially transformed to acetic multistep process involving energy-intensive steam reforming, synthesis, and, subsequently, carbonylation. Here, we report direct single-step conversion molecular oxygen (O2) as the oxidant under mild conditions over mono-copper hydroxyl site confined in porous cerium metal–organic framework (MOF), Ce-UiO-Cu(OH). The Ce-UiO MOF-supported single-site copper catalyst gave exceptionally high productivity 335 mmolgcat–1 96% selectivity with Cu TON up 400 at 115 °C water. Our spectroscopic and theoretical studies controlled experiments reveal that occurs oxidative carbonylation, where first activated σ-bond metathesis afford Cu-methyl species, followed by situ-generated carbon monoxide subsequent hydrolysis This work may guide rational design heterogeneous abundant metal catalysts for activation other valuable chemicals environmentally friendly reaction conditions.

Language: Английский

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Highly Robust Metal–Organic Framework for Efficiently Catalyzing Knoevenagel Condensation and the Strecker Reaction under Solvent-Free Conditions

Inorganic Chemistry, Journal Year: 2023, Volume and Issue: 62(32), P. 12989 - 13000

Published: Aug. 2, 2023

Metal–organic frameworks (MOFs) have been recognized as one of the most promising porous materials and offer great opportunities for rational design new catalytic solids having structural diversity functional tunability. Despite numerous inherent merits, their chemical environment instability limits practical usage demands further exploration. Herein, by employing mixed-ligand approach, we designed developed a robust 3D Co-MOF, [Co2(μ2-O)(TDC)2(L)(H2O)2]·2DMF (H2TDC = 2,5-thiophenedicarboxylic acid, L 3,3′-azobispyridine), IITKGP-50 (IITKGP stands Indian Institute Technology Kharagpur), which exhibited excellent framework robustness not only in water but also wide range aqueous pH solutions (pH 2–12). Taking advantage superior presence high-density open metal sites, was explored catalyzing two-component Knoevenagel condensation reaction three-component Strecker reactions. Moreover, to verify size selectivity IITKGP-50, smaller bulkier substrates comparison with MOF's pore cavity (8.1 × 5.6 Å2) were employed, relatively lesser conversions sterically aldehyde derivatives confirmed that cycle occurs inside cavity. The easy scalability, lower catalyst loading compared benchmark MOFs, magnificent conversion rate over substrates, recyclability without significant performance loss made heterogeneous candidate.

Language: Английский

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Synergetic Ni–Ce Active Sites in Mixed Cerium/Zirconium Metal–Organic Framework Nodes for Selective Methane Oxidation into Ethanol

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(14), P. 10427 - 10436

Published: June 26, 2024

The direct oxidation of methane into ethanol with high productivity under mild conditions is a grand challenge. We report the development mixed cerium/zirconium metal–organic framework (MOF) nodes-supported mononuclear nickel(II)-hydroxyl species [Cex/Zry–UiO–Ni(OH)] as efficient heterogeneous catalysts for transformation ethanol. Ni2+ ion in Cex/Zry–UiO–Ni(OH) MOFs coordinates μ4–O–, one hydroxy group, and two neutral carboxylate oxygens, which are directly bonded to Ce4+ at metal-oxo nodes. spectroscopic control experiments theoretical calculations reveal that precise composition mixed-metal node, isolation mono Ni-hydroxyl cooperative Ni–Ce active sites confined within porous UiO-MOFs promote facile C–H activation 80 °C, leading formation •CH3 radicals subsequent C–C coupling pores produce an extraordinarily yield 6521 mmol gNi–1 >93% selectivity, outperforming most current reports. Our mechanistic investigation suggests proceeds via dual catalytic cycle, doping MOF's node proximity between ions lead reversible Ce–Ocarboxylate bond dissociation Ni–(μ2–OH)–Ce formation, key radical turnover limiting step. This work highlights importance metal-MOFs designing well-defined heterobimetallic-supported valorization light alkanes catalysis.

Language: Английский

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Advances on silver-based MOFs and/or CPs and their composites: Synthesis strategies and applications

Coordination Chemistry Reviews, Journal Year: 2024, Volume and Issue: 514, P. 215924 - 215924

Published: May 11, 2024

Language: Английский

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Copper Catalyzed Selective Methane Oxidation into Acetic Acid using O2

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A porous aluminium metal–organic framework confined mono-copper( ii ) hydroxyl species serves as an efficient catalyst for the direct conversion of methane into acetic acid using O 2 oxidant in water with excellent productivity and selectivity.

Language: Английский

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MOF-based catalysts: insights into the chemical transformation of greenhouse and toxic gases

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(68), P. 10226 - 10242

Published: Jan. 1, 2023

Metal-organic framework (MOF)-based catalysts are outstanding alternative materials for the chemical transformation of greenhouse and toxic gases into high-add-value products. MOF exhibit remarkable properties to host different active sites. The combination catalytic MOFs is mentioned in order understand their application. Furthermore, main reactions, which involve CH4, CO2, NOx, fluorinated gases, O3, CO, VOCs, H2S, highlighted. centers reaction conditions these reactions presented discussed mechanisms. Interestingly, implementing as gas-phase a great opportunity provide new alternatives enhance air quality our planet.

Language: Английский

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Full Spectroscopic Characterization of the Molecular Oxygen-Based Methane to Methanol Conversion over Open Fe(II) Sites in a Metal–Organic Framework

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(38), P. 21040 - 21052

Published: Sept. 18, 2023

Iron-based enzymes efficiently activate molecular oxygen to perform the oxidation of methane methanol (MTM), a reaction central contemporary chemical industry. Conversely, very limited number artificial catalysts have been devised mimic this process. Herein, we employ MIL-100(Fe) metal-organic framework (MOF), material that exhibits isolated Fe sites, accomplish MTM conversion using O2 as oxidant under mild conditions. We apply diverse set advanced operando X-ray techniques unveil how can act catalyst for direct conversion. Single-phase crystallinity and stability MOF conditions (200 or 100 °C, CH4 + O2) are confirmed by diffraction measurements. absorption, emission, resonant inelastic scattering measurements show thermal treatment above 200 °C generates Fe(II) sites interact with produce methanol. Experimental evidence-driven density functional theory (DFT) calculations illustrate involves Fe(III) via high-spin Fe(IV)═O intermediate. Catalyst deactivation is proposed be caused escape CH3• radicals from relatively large pore cages, ultimately resulting in formation hydroxylated triiron units, proven valence-to-core emission spectroscopy. The O2-based catalytic activity investigated demonstrated two consecutive cycles, proving potential toward active site regeneration. These findings will desirably lay groundwork design improved

Language: Английский

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