Single active-site catalysts constructed with nonpolar-bond linked covalent organic frameworks for oxygen reduction reaction

Science China Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 24, 2025

Language: Английский

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Zwitterionic covalent organic framework triggering enhanced H2O2 photoproduction via controllable built-in electric field design

Chemical Engineering Journal, Journal Year: 2025, Volume and Issue: unknown, P. 161631 - 161631

Published: March 1, 2025

Language: Английский

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10% Conversion of Imine into Thiazole in Covalent Organic Frameworks for Efficient Photocatalytic H₂O₂ Generation

Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown

Published: March 17, 2025

Abstract The 5–10 nm exciton diffusion distance for most organic semiconductors is much less than the particle size of 2D covalent frameworks (COFs). As a result, local structure change in small domain COFs, rather whole particles, could effectively promote charge transfer photocatalysis. Herein, three‐component condensation used to preparing four mixed imine‐ and thiazole‐linked donor‐acceptor (D–A) COFs. In contrast 100% imine ca. 90% 10% materials have 77–95% higher photocatalytic hydrogen peroxide (H 2 O ) production rate pure water due more prolonged lifetime excitation state. particular, USTB‐10‐S exhibits H generation 5041 µmol g −1 h . Coupling with benzyl alcohol as sacrificial reagent, its further increased 16152 , superior COF‐based photocatalysts. This work illustrates proof‐of‐concept that COFs tiny amount able significantly enhance separation thus performance, inspiring development defect engineering field

Language: Английский

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Ionic covalent organic framework-MXene heterojunction constructed by electrostatic interaction for stable electrocatalytic hydrogen generation

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: unknown, P. 156033 - 156033

Published: Sept. 1, 2024

Language: Английский

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Modulating Pore Sizes and Electronic Properties of Covalent Organic Polymers for the Catalysis of Two-Electron Oxygen Reduction Reaction in Neutral Media

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(18), P. 13883 - 13891

Published: Sept. 4, 2024

Language: Английский

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Application of Nanocomposites in Covalent Organic Framework-Based Electrocatalysts

Nanomaterials, Journal Year: 2024, Volume and Issue: 14(23), P. 1907 - 1907

Published: Nov. 27, 2024

In recent years, the development of high-performance electrocatalysts for energy conversion and environmental remediation has become a topic great interest. Covalent organic frameworks (COFs), linked by covalent bonds, have emerged as promising materials in field electrocatalysis due to their well-defined structures, high specific surface areas, tunable pore excellent acid-base stability. However, low conductivity COF often limits intrinsic electrocatalytic activity. To enhance catalytic performance COF-based catalysts, various nanomaterials are integrated into COFs form composite catalysts. The stable porous structure provides an ideal platform these nanomaterials, leading improved Through rational design, can achieve synergistic effects between carrier, enabling efficient targeted electrocatalysis. This review summarizes applications nanomaterial-incorporated catalysts hydrogen evolution, oxygen reduction, carbon dioxide nitrogen reduction. Additionally, it outlines design principles electrocatalysis, focusing on structure-activity relationships nanomaterial electrocatalysts, well challenges future perspectives next-generation electrocatalysts.

Language: Английский

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The steric hindrance effect of Co porphyrins promoting two-electron oxygen reduction reaction selectivity

Chemical Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 19, 2024

A new Co porphyrin with eight ester groups in ortho and ′ positions of phenyl was designed, which displayed improved 2e oxygen reduction reaction (ORR) selectivity compared a without large steric groups.

Language: Английский

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Hydrogen radical enabling industrial‐level oxygen electroreduction to hydrogen peroxide

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 22, 2024

Abstract The electrochemical synthesis of hydrogen peroxide from oxygen and water, powered by renewable electricity, provides a highly attractive alternative to the energy‐intensive autoxidation process presently used in industry, but much remains unknown about this two‐electron reduction reaction (2e‐ORR), especially local proton effect. Here, we have investigated function hydrogen‐associated intermediates 2e‐ORR using rationally designed cooperative electrode material with cobalt (II) clusters embedded onto oxidized carbon nanotube composites (Co‐OCNT). We found that availability can determine both kinetics selectivity. A involving radical transfer is confirmed. Specifically, sites OCNTs promote production, Co cluster facilitate ORR intermediate formation. high dual‐active contribute superior selectivity Co‐OCNT, reaching an H 2 O production rate ~40.6 mol g cat −1 h faradaic efficiency 90 % at current density 300 mA cm −2 . Further cascading electro‐Fenton shows oxalic acid up 97 for valorization ethylene glycol.

Language: Английский

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Hydrogen radical enabling industrial‐level oxygen electroreduction to hydrogen peroxide

Angewandte Chemie, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 22, 2024

Abstract The electrochemical synthesis of hydrogen peroxide from oxygen and water, powered by renewable electricity, provides a highly attractive alternative to the energy‐intensive autoxidation process presently used in industry, but much remains unknown about this two‐electron reduction reaction (2e‐ORR), especially local proton effect. Here, we have investigated function hydrogen‐associated intermediates 2e‐ORR using rationally designed cooperative electrode material with cobalt (II) clusters embedded onto oxidized carbon nanotube composites (Co‐OCNT). We found that availability can determine both kinetics selectivity. A involving radical transfer is confirmed. Specifically, sites OCNTs promote production, Co cluster facilitate ORR intermediate formation. high dual‐active contribute superior selectivity Co‐OCNT, reaching an H 2 O production rate ~40.6 mol g cat −1 h faradaic efficiency 90 % at current density 300 mA cm −2 . Further cascading electro‐Fenton shows oxalic acid up 97 for valorization ethylene glycol.

Language: Английский

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Manipulating Metal Cations Microenvironment for Highly Selective Electrochemical Water Oxidation to Hydrogen Peroxide

ACS Catalysis, Journal Year: 2024, Volume and Issue: 15(1), P. 193 - 200

Published: Dec. 16, 2024

Electrochemical two-electron water oxidation (2e– WOR) represents a promising approach for the renewable and on-site production of H2O2, potentially replacing anthraquinone process. Nevertheless, it faces intense competition from conventional four-electron oxygen evolution reaction (OER), resulting in low selectivity, high overpotential, yield. Herein, taking carbon-based structures with 2e– WOR selectivity as model catalysts, by manipulating electrolyte, increased maximum Faraday efficiency H2O2 to 71 ± 3%, an rate 11.7 μmol cm–2 min–1. The activity was found be most sensitive alkali metal cations following order: Cs+ > K+ Na+ Li+. In situ spectroscopy characterization confirmed that larger facilitate generation peroxide species; this is because, on one hand, can regulate electronic catalyst sites improve adsorption intermediates; other cation-hydrogen interaction regulates stable coordination cation, realizes reforming hydrogen bond network, prevents its further into O2. With help flow electro-synthetic cell, we successfully achieve rapid degradation organic pollutants preparation solid (sodium peroxycarbonate). This work not only enriches understanding cationic mechanisms but also provides implications rational optimization strategies electrode/electrolyte interface.

Language: Английский

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