Mesopore‐Rich Fe–N–C Catalyst with FeN₄–O–NC Single‐Atom Sites Delivers Remarkable Oxygen Reduction Reaction Performance in Alkaline Media

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(29)

Published: May 18, 2022

Fe-N-C catalysts offer excellent performance for the oxygen reduction reaction (ORR) in alkaline media. With a view toward boosting intrinsic ORR activity of Fe single-atom sites catalysts, fine-tuning local coordination to optimize binding energies intermediates is imperative. Herein, porous FeN4 -O-NCR electrocatalyst rich catalytically accessible -O (wherein single atoms are coordinated four in-plane nitrogen and one subsurface axial atom) supported on N-doped carbon nanorods (NCR) reported. K-edge X-ray absorption spectroscopy (XAS) verifies presence active -O-NCR, while density functional theory calculations reveal that offers lower energy more selective 4-electron/4-proton pathway compared traditional sites. Electrochemical tests validate outstanding ORR, outperforming Pt/C almost all other M-N-C reported date. A primary zinc-air battery constructed using delivers peak power 214.2 mW cm-2 at current 334.1 mA , highlighting benefits optimizing iron atoms.

Language: Английский

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Atomically Dispersed Co₂–N₆ and Fe–N₄ Costructures Boost Oxygen Reduction Reaction in Both Alkaline and Acidic Media

Advanced Materials, Journal Year: 2021, Volume and Issue: 33(49)

Published: Oct. 8, 2021

Abstract Polynary transition‐metal atom catalysts are promising to supersede platinum (Pt)‐based for oxygen reduction reaction (ORR). Regulating the local configuration of atomic is key catalyst performance enhancement. Different from previously reported single‐atom or dual‐atom configurations, a new type ternary‐atom catalyst, which consists atomically dispersed, nitrogen‐coordinated Co–Co dimers, and Fe single sites (i.e., Co 2 –N 6 Fe–N 4 structures) that coanchored on highly graphitized carbon supports developed. This unique ORR outperforms with only in both alkaline acid conditions. Density functional theory calculations clearly unravels synergistic effect sites, can induce higher filling degree Fe–d orbitals favors binding capability *OH intermediates (the rate determining step). may be alternative Pt drive cathodic zinc–air batteries.

Language: Английский

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Semiconducting Polymers for Oxygen Evolution Reaction under Light Illumination

Chemical Reviews, Journal Year: 2022, Volume and Issue: 122(3), P. 4204 - 4256

Published: Jan. 13, 2022

Sunlight-driven water splitting to produce hydrogen fuel has stimulated intensive scientific interest, as this technology the potential revolutionize fossil fuel-based energy systems in modern society. The oxygen evolution reaction (OER) determines performance of overall owing its sluggish kinetics with multielectron transfer processing. Polymeric photocatalysts have recently been developed for OER, and substantial progress realized emerging research field. In Review, focus is on photocatalytic technologies materials polymeric OER. Two practical systems, namely, particle suspension film-based photoelectrochemical form two main sections. concept reviewed terms thermodynamics kinetics, are discussed based three key characteristics, light absorption, charge separation transfer, surface oxidation reactions. A satisfactory OER by will eventually offer a platform achieve other advanced applications cost-effective, sustainable, renewable manner using solar energy.

Language: Английский

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Multifunctional TiO2/C nanosheets derived from 3D metal–organic frameworks for mild-temperature-photothermal-sonodynamic-chemodynamic therapy under photoacoustic image guidance

Journal of Colloid and Interface Science, Journal Year: 2022, Volume and Issue: 621, P. 360 - 373

Published: April 14, 2022

Language: Английский

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Construction of N, P Co‐Doped Carbon Frames Anchored with Fe Single Atoms and Fe ₂ P Nanoparticles as a Robust Coupling Catalyst for Electrocatalytic Oxygen Reduction

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(29)

Published: May 24, 2022

A coupling catalyst of highly dispersed N, P co-doped carbon frames (NPCFs) anchored with Fe single atoms (SAs) and Fe2 nanoparticles (NPs) is synthesized by a novel in situ doping-adsorption-phosphatization strategy for the electrocatalytic oxygen reduction reaction (ORR). The optimized SAs-Fe2 NPs/NPCFs-2.5 shows superior ORR activity stability 0.5 m H2 SO4 0.1 KOH, respectively. Theoretical calculations reveal synergistic effect, that existence weakens adsorption intermediates on active sites lowers free energy. doped strong electron-donating ability elevate energy level Fe-3d orbitals facilitate O2 . exist low oxidation state are less positively charged, they serve as an electron reservoir capable donating releasing electrons, thus improving activity. Operando characterization results indicate atomically FeN4 /FeP coupled centers characteristic different catalytic mechanisms acidic alkaline media. This work proposes idea constructing catalysts atomic-level precision provides reference development high-efficiency electrocatalysts practical application.

Language: Английский

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Site-Specified Two-Dimensional Heterojunction of Pt Nanoparticles/Metal–Organic Frameworks for Enhanced Hydrogen Evolution

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(40), P. 16512 - 16518

Published: Oct. 4, 2021

Heterojunction nanostructures usually exhibit enhanced properties in compariosn with their building blocks and are promising catalyst candidates due to combined surface unique interface. Here, for the first time we realized oriented growth of ultrasmall metal nanoparticles (NPs) on metal–organic framework nanosheets (MOF NSs) by precisely regulating reduction kinetics ions solvents. In particular, a rapid leads random distribution NPs MOF NSs, while slow results edge NSs. Impressively, strong synergy between Pt NSs significantly enhances hydrogen evolution reaction (HER) performance, optimal displays HER activities superior those composite commercial Pt/C under both acidic alkaline conditions. Moreover, versatility such has been extended other NPs, as Pd, Ag, Au. We believe this work will promote research interest material design many potential applications.

Language: Английский

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Single atoms meet metal–organic frameworks: collaborative efforts for efficient photocatalysis

Energy & Environmental Science, Journal Year: 2022, Volume and Issue: 15(9), P. 3722 - 3749

Published: Jan. 1, 2022

MOF-supported single atom materials offer great potential for design and engineering of advanced photocatalysts energy conversion applications. State-of-the-art prospects in recent breakthroughs are presented this review.

Language: Английский

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Graphene‐Supported Atomically Dispersed Metals as Bifunctional Catalysts for Next‐Generation Batteries Based on Conversion Reactions

Advanced Materials, Journal Year: 2021, Volume and Issue: 34(5)

Published: Oct. 22, 2021

Next-generation batteries based on conversion reactions, including aqueous metal-air batteries, nonaqueous alkali metal-O2 and -CO2 metal-chalcogen metal-ion have attracted great interest. However, their use is restricted by inefficient reversible of active agents. Developing bifunctional catalysts to accelerate the reaction kinetics in both discharge charge processes urgently needed. Graphene-, or graphene-like carbon-supported atomically dispersed metal (G-ADMCs) been demonstrated show excellent activity various electrocatalytic making them promising candidates. Different from G-ADMCs for catalysis, which only require high one direction, rechargeable should provide discharging charging. This review provides guidance design fabrication next-generation reactions. The key challenges that prevent conversion, origin G-ADMCs, current principles highly analyzed highlighted each conversion-type battery. Finally, a summary outlook development G-ADMC materials with energy density efficiency are given.

Language: Английский

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Breaking Local Charge Symmetry of Iron Single Atoms for Efficient Electrocatalytic Nitrate Reduction to Ammonia

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(39)

Published: July 22, 2023

The electrochemical conversion of nitrate pollutants into value-added ammonia is a feasible way to achieve artificial nitrogen cycle. However, the development electrocatalytic nitrate-to-ammonia reduction reaction (NO3- RR) has been hampered by high overpotential and low Faradaic efficiency. Here we develop an iron single-atom catalyst coordinated with phosphorus on hollow carbon polyhedron (denoted as Fe-N/P-C) NO3- RR electrocatalyst. Owing tuning effect atoms breaking local charge symmetry single-Fe-atom catalyst, it facilitates adsorption ions enrichment some key intermediates during process. Fe-N/P-C exhibits 90.3 % efficiency yield rate 17980 μg h-1 mgcat-1 , greatly outperforming reported Fe-based catalysts. Furthermore, operando SR-FTIR spectroscopy measurements reveal pathway based observed under different applied potentials durations. Density functional theory calculations demonstrate that optimized free energy ascribed asymmetric atomic interface configuration, which achieves optimal electron density distribution. This work demonstrates critical role atomic-level precision modulation heteroatom doping for RR, providing effective strategy improving catalytic performance single atom catalysts in reactions.

Language: Английский

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Strategic design of Fe and N co-doped hierarchically porous carbon as superior ORR catalyst: from the perspective of nanoarchitectonics

Chemical Science, Journal Year: 2022, Volume and Issue: 13(36), P. 10836 - 10845

Published: Jan. 1, 2022

This study elucidates the role of each class nanopore by in-depth electrochemical analysis three types ZIF-8-derived carbons. Also, engineered co-doping Fe and N is found essential to selectively form Fe–N x sites in carbon matrix.

Language: Английский

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