Methane Oxidation to Methanol Catalyzed by Cu-Oxo Clusters Stabilized in NU-1000 Metal–Organic Framework

Journal of the American Chemical Society, Год журнала: 2017, Номер 139(30), С. 10294 - 10301

Опубликована: Июнь 14, 2017

Copper oxide clusters synthesized via atomic layer deposition on the nodes of metal–organic framework (MOF) NU-1000 are active for oxidation methane to methanol under mild reaction conditions. Analysis chemical reactivity, in situ X-ray absorption spectroscopy, and density functional theory calculations used determine structure/activity relations Cu-NU-1000 catalytic system. The Cu-loaded MOF contained Cu-oxo a few Cu atoms. was present ambient conditions as mixture ∼15% Cu+ ∼85% Cu2+. accompanied by reduction 9% catalyst from Cu2+ Cu+. products, methanol, dimethyl ether, CO2, were desorbed with passage 10% water/He at 135 °C, giving carbon selectivity 45–60%. oxo stabilized provide an active, first generation MOF-based, selective catalyst.

Язык: Английский

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Advances in methane conversion processes

Catalysis Today, Год журнала: 2017, Номер 285, С. 147 - 158

Опубликована: Фев. 14, 2017

Язык: Английский

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Stability and reactivity of copper oxo-clusters in ZSM-5 zeolite for selective methane oxidation to methanol

Journal of Catalysis, Год журнала: 2016, Номер 338, С. 305 - 312

Опубликована: Апрель 4, 2016

Язык: Английский

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Methane conversion into different hydrocarbons or oxygenates: current status and future perspectives in catalyst development and reactor operation

Catalysis Science & Technology, Год журнала: 2016, Номер 7(2), С. 366 - 381

Опубликована: Дек. 13, 2016

This Perspective highlights recent developments in methane conversion into different hydrocarbons and C₁-oxygenates. Our analysis identified possible directions for further research to bring the above approaches a commercial level.

Язык: Английский

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Formation of [Cu₂O₂]²⁺ and [Cu₂O]²⁺ toward C–H Bond Activation in Cu-SSZ-13 and Cu-SSZ-39

ACS Catalysis, Год журнала: 2017, Номер 7(7), С. 4291 - 4303

Опубликована: Май 18, 2017

Cu-exchanged small-pore zeolites (CHA and AEI) form methanol from methane (>95% selectivity) using a 3-step cyclic procedure (Wulfers et al. Chem. Commun. 2015, 51, 4447−4450) with amounts higher than Cu-ZSM-5 Cu-mordenite on per gram Cu basis. Here, the CuxOy species formed Cu-SSZ-13 Cu-SSZ-39 following O2 or He activation at 450 °C are identified as trans-μ-1,2-peroxo dicopper(II) ([Cu2O2]2+) mono-(μ-oxo) ([Cu2O]2+) synchrotron X-ray diffraction, in situ UV–vis, Raman spectroscopy theory. [Cu2O2]2+ [Cu2O]2+ showed ligand-to-metal charge transfer (LMCT) energies between 22,200 35,000 cm–1, Cu–O vibrations 360, 510, 580, 617 cm–1 an O–O vibration 837 cm–1. The assigned to species, whereas (Δ18O = 24 cm–1) is stretching of thermodynamically favored Cu–O–Cu angle 95°. On basis intensity loss broad LMCT band 571 upon reaction, both suggested take part 200 core playing dominant role. A relationship [Cu2Oy]2+ concentration Cu(II) eight-membered ring observed related [CuOH]+ intermediate formation.

Язык: Английский

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Active sites and mechanisms in the direct conversion of methane to methanol using Cu in zeolitic hosts: a critical examination

Chemical Society Reviews, Год журнала: 2020, Номер 49(5), С. 1449 - 1486

Опубликована: Янв. 1, 2020

In this critical review we examine the current state of our knowledge in respect nature active sites copper containing zeolites for selective conversion methane to methanol. We consider varied experimental evidence arising from application X-ray diffraction, and vibrational, electronic, spectroscopies that exist, along with results theory. aim establish both what is known regarding these elusive materials how they function, also where gaps still offer suggestions strategies as might be closed such rational design more effective efficient type proceed further.

Язык: Английский

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The Nuclearity of the Active Site for Methane to Methanol Conversion in Cu-Mordenite: A Quantitative Assessment

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(45), С. 15270 - 15278

Опубликована: Окт. 22, 2018

The direct conversion of methane to methanol (MTM) is a reaction that has the potential disrupt great part synthesis gas-derived chemical industry. However, despite many decades research, active enough catalysts and suitable processes for industrial application are still not available. Recently, several copper-exchanged zeolites have shown considerable activity selectivity in MTM reaction. Understanding nature site these materials essential any further development field. Herein, we apply multivariate curve resolution analysis X-ray absorption spectroscopy data accurately quantify fraction Cu Cu-MOR (MOR = mordenite), allowing an unambiguous determination nuclearity as dicopper site. By rationalizing compositional parameters conditions, achieve highest yield per yet reported over Cu-zeolites, 0.47 mol/mol.

Язык: Английский

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Monocopper Active Site for Partial Methane Oxidation in Cu-Exchanged 8MR Zeolites

ACS Catalysis, Год журнала: 2016, Номер 6(10), С. 6531 - 6536

Опубликована: Авг. 17, 2016

Direct conversion of methane to methanol using oxygen is experiencing renewed interest owing the availability new natural gas resources. Copper-exchanged zeolites such as mordenite and ZSM-5 have shown encouraging results, di- tri-copper species been suggested active sites. Recently, small eight-membered ring (8MR) including SSZ-13, -16, -39 be for oxidation, but sites reaction mechanisms in these 8MR are not known. In this work, we use density functional theory (DFT) calculations systematically evaluate monocopper partial oxidation Cu-exchanged SSZ-13. On basis kinetic thermodynamic arguments, suggest that [CuIIOH]+ responsible experimentally observed activity. Our results successfully explain available spectroscopic data experimental observations (i) necessity water extraction (ii) effect Si/Al ratio on catalyst Monocopper yet an site reaction, our may provide complementary routes activation addition known [Cu–O–Cu]2+ Cu3O3 motifs.

Язык: Английский

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Misconceptions and challenges in methane-to-methanol over transition-metal-exchanged zeolites

Nature Catalysis, Год журнала: 2019, Номер 2(6), С. 485 - 494

Опубликована: Май 20, 2019

Язык: Английский

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Methane Oxidation to Methanol

Chemical Reviews, Год журнала: 2022, Номер 123(9), С. 6359 - 6411

Опубликована: Дек. 2, 2022

The direct transformation of methane to methanol remains a significant challenge for operation at larger scale. Central this is the low reactivity conditions that can facilitate product recovery. This review discusses issue through examination several promising routes and an evaluation performance targets are required develop process We explore methods currently used, emergence active heterogeneous catalysts their design reaction mechanisms provide critical perspective on future operation. Initial experiments discussed where identification gas phase radical chemistry limited further development by approach. Subsequently, new class catalytic materials based natural systems such as iron or copper containing zeolites were explored milder conditions. key issues these technologies conversion often overoxidation products. Despite this, interest high in wider appeal effective route products from C–H activation, particularly with need transition net carbon zero renewable sources exciting.

Язык: Английский

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