Cocatalysts in photocatalytic methane conversion: recent achievements and prospects

Zhang, Chengcheng; Wang, Jing; Ouyang, Shenshen; Song, Hui; Ye, Jinhua; Shi, Li

doi:10.1007/s11426-023-1737-2

“…Product Analysis. The contents of CH 3 OOH, CH 3 OH, and HCOOH in the reaction solution were analyzed by 1 H NMR (AVANCE NEO 600 MHz). Typically, 0.4 mL of liquid product was mixed with 0.1 mL of D 2 O; dimethyl sulfoxide (DMSO, 99.99%) was added as an internal standard substance; and the DMSO proton peak area was compared with the product peak area as the quantity of the product.…”

Section: Photocatalytic Methane Conversionmentioning

confidence: 99%

“…Methane (CH 4 ) as the main components of natural gas abundant in the earth plays an important role in industrial production. − Upgrading CH 4 to high value oxygenates not only provides the required raw material intermediates for the chemical industry but also effectively reduces the transportation cost of CH 4 . , Photocatalysis as an advanced green technology could utilize light energy to trigger high reactive energy barrier reactions, providing a method for directly converting CH 4 into liquid oxygenates. , Nevertheless, the inherent high bond energy and low polarization of the C–H bond seriously hinder the efficiency of CH 4 conversion. − Moreover, liquid oxygenates are more prone to overoxidation to CO 2 than CH 4 . − Therefore, searching for photocatalysts with high efficiency and selectivity to liquid oxygenates is the core of CH 4 conversion.…”

Section: Introductionmentioning

confidence: 99%

Interstitial Zinc Defects Enriched ZnO Tuning O₂ Adsorption and Conversion Pathway for Superior Photocatalytic CH₄ Oxygenation

Xiao,

Wan,

Zhang

et al. 2024

ACS Catal.

0

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Photocatalytic methane conversion into liquid oxygenates using O 2 oxidants provides a promising approach for high-value chemicals. The generation of reactive oxygen species and their reaction pathway are key to determine the oxygenate selectivity. Here, an interstitial Zn i defect ZnO (ZnO(Zn i )) is developed through thermal decomposition of the ZnO 2 precursor. Zn i favors the O 2 adsorption at a terminal adsorption configuration and induces effectively the conversion O 2 into the desired •OOH instead of •OH for improving the yield and selectivity of oxygenates. For comparison, O 2 adsorbed in a lateral configuration tends to be converted into excessive •OH on the typical Au/ZnO. As a result, ZnO(Zn i ) shows the liquid oxygenates yield of 6080 μmol g −1 with 98.6% selectivity, which leads to 10 times lower than Au/ZnO for CO 2 release of overoxidation. This work provides a pathway for O 2 adsorption and activation to regulate the photocatalytic CH 4 oxidation conversion into liquid oxygenates.

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Contact‐Electro‐Catalysis for Direct Oxidation of Methane under Ambient Conditions

Li,

Sun,

Wang

et al. 2024

Angewandte Chemie

1

0

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The conversion of methane under ambient conditions has attracted significant attention. Although advancements have been made using active oxygen species from photo‐ and electro‐ chemical processes, challenges such as complex catalyst design, costly oxidants, and unwanted byproducts remain. This study exploits the concept of contact‐electro‐catalysis, initiating chemical reactions through charge exchange at a solid‐liquid interface, to report a novel process for directly converting methane under ambient conditions. Utilizing the electrification of commercially available Fluorinated Ethylene Propylene (FEP) with water under ultrasound, we demonstrate how this interaction promote the activation of methane and oxygen molecules. Our results show that the yield of HCHO and CH3OH can reach 467.5 and 151.2 μmol·gcat‐1, respectively. We utilized electron paramagnetic resonance (EPR) to confirm the evolution of hydroxyl radicals (·OH) and superoxide radicals (·OOH). Isotope mass spectrometry (MS) was employed to analyze the elemental origin of CH3OH, which can be further oxidized to HCHO. Additionally, we conducted density functional theory (DFT) simulations to assess the reaction energies of FEP with H2O, O2, and CH4 under these conditions. The implications of this methodology, with its potential applicability to a wider array of gas‐phase catalytic reactions, underscore a significant advance in catalysis.

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Contact‐Electro‐Catalysis for Direct Oxidation of Methane under Ambient Conditions

Li,

Sun,

Wang

et al. 2024

Angew Chem Int Ed

3

0

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The conversion of methane under ambient conditions has attracted significant attention. Although advancements have been made using active oxygen species from photo‐ and electro‐ chemical processes, challenges such as complex catalyst design, costly oxidants, and unwanted byproducts remain. This study exploits the concept of contact‐electro‐catalysis, initiating chemical reactions through charge exchange at a solid‐liquid interface, to report a novel process for directly converting methane under ambient conditions. Utilizing the electrification of commercially available Fluorinated Ethylene Propylene (FEP) with water under ultrasound, we demonstrate how this interaction promote the activation of methane and oxygen molecules. Our results show that the yield of HCHO and CH3OH can reach 467.5 and 151.2 μmol·gcat‐1, respectively. We utilized electron paramagnetic resonance (EPR) to confirm the evolution of hydroxyl radicals (·OH) and superoxide radicals (·OOH). Isotope mass spectrometry (MS) was employed to analyze the elemental origin of CH3OH, which can be further oxidized to HCHO. Additionally, we conducted density functional theory (DFT) simulations to assess the reaction energies of FEP with H2O, O2, and CH4 under these conditions. The implications of this methodology, with its potential applicability to a wider array of gas‐phase catalytic reactions, underscore a significant advance in catalysis.

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Cocatalysts in photocatalytic methane conversion: recent achievements and prospects

Cited by 6 publications

References 153 publications

Interstitial Zinc Defects Enriched ZnO Tuning O₂ Adsorption and Conversion Pathway for Superior Photocatalytic CH₄ Oxygenation

Interstitial Zinc Defects Enriched ZnO Tuning O₂ Adsorption and Conversion Pathway for Superior Photocatalytic CH₄ Oxygenation

Contact‐Electro‐Catalysis for Direct Oxidation of Methane under Ambient Conditions

Contact‐Electro‐Catalysis for Direct Oxidation of Methane under Ambient Conditions

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Cocatalysts in photocatalytic methane conversion: recent achievements and prospects

Cited by 6 publications

References 153 publications

Interstitial Zinc Defects Enriched ZnO Tuning O2 Adsorption and Conversion Pathway for Superior Photocatalytic CH4 Oxygenation

Interstitial Zinc Defects Enriched ZnO Tuning O2 Adsorption and Conversion Pathway for Superior Photocatalytic CH4 Oxygenation

Contact‐Electro‐Catalysis for Direct Oxidation of Methane under Ambient Conditions

Contact‐Electro‐Catalysis for Direct Oxidation of Methane under Ambient Conditions

Contact Info

Product

Resources

About

Interstitial Zinc Defects Enriched ZnO Tuning O₂ Adsorption and Conversion Pathway for Superior Photocatalytic CH₄ Oxygenation

Interstitial Zinc Defects Enriched ZnO Tuning O₂ Adsorption and Conversion Pathway for Superior Photocatalytic CH₄ Oxygenation