Single‐Atom Fe Catalysts for Fenton‐Like Reactions: Roles of Different N Species

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(17)

Published: March 8, 2022

Recognizing and controlling the structure-activity relationships of single-atom catalysts (SACs) is vital for manipulating their catalytic properties various practical applications. Herein, Fe SACs supported on nitrogen-doped carbon (SA-Fe/CN) are reported, which show high reactivity (97% degradation bisphenol A in only 5 min), stability (80% maintained after five runs), wide pH suitability (working range 3-11) toward Fenton-like reactions. The roles different N species these reactions further explored, both experimentally theoretically. It discovered that graphitic an adsorptive site target molecule, pyrrolic coordinates with Fe(III) plays a dominant role reaction, pyridinic N, coordinated Fe(II), minor contributor to SA-Fe/CN. Density functional theory (DFT) calculations reveal lower d-band center location pyrrolic-type sites leads easy generation Fe-oxo intermediates, thus, excellent properties.

Language: Английский

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Single-Atom (Iron-Based) Catalysts: Synthesis and Applications

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(21), P. 13620 - 13697

Published: Oct. 13, 2021

Supported single-metal atom catalysts (SACs) are constituted of isolated active metal centers, which heterogenized on inert supports such as graphene, porous carbon, and oxides. Their thermal stability, electronic properties, catalytic activities can be controlled via interactions between the center neighboring heteroatoms nitrogen, oxygen, sulfur. Due to atomic dispersion amount required for catalysis decreased, thus offering new possibilities control selectivity a given transformation well improve catalyst turnover frequencies numbers. This review aims comprehensively summarize synthesis Fe-SACs with focus anchoring single atoms (SA) carbon/graphene supports. The characterization these advanced materials using various spectroscopic techniques their applications in diverse research areas described. When applicable, mechanistic investigations conducted understand specific behavior Fe-SACs-based highlighted, including use theoretical models.

Language: Английский

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Synthesis Strategies, Catalytic Applications, and Performance Regulation of Single‐Atom Catalysts

Advanced Functional Materials, Journal Year: 2021, Volume and Issue: 31(12)

Published: Jan. 4, 2021

Abstract The recent dramatic increase in research on isolated metal atoms has received extensive scientific interest the new frontier of single‐atom catalysis. As newly advanced materials catalysis, catalysts (SACs) have enormous from perspectives both and industrial applications due to their remarkable activity. In addition, other catalytic properties single atoms, including stability selectivity, can be further improved by tuning electronic/geometric structures modulating metal–support interactions. SACs usually consist dispersed appropriate support materials, which are employed anchor, confine, and/or coordinate with atoms. Therefore, nature sites allows acquiring a maximum atom utilization approaching 100%, is significance, particularly for development noble‐metal‐based catalysts. order systematically understand structure–property relationships underlying mechanisms relationship SACs, representative efforts synthesis strategies, applications, performance regulation discussed here. Typical catalysis processes corresponding electrochemistry, photochemistry, organic synthesis, biomedicine also summarized. Finally, challenges prospects highlighted.

Language: Английский

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Single‐Atom Catalysts: A Sustainable Pathway for the Advanced Catalytic Applications

Small, Journal Year: 2021, Volume and Issue: 17(16)

Published: Feb. 24, 2021

A heterogeneous catalyst is a backbone of modern sustainable green industries; and understanding the relationship between its structure properties key for advancement. Recently, many upscaling synthesis strategies development variety respectable control atomically precise catalysts are reported explored various important applications in catalysis energy environmental remediation. Precise atomic-scale has allowed to significantly increase activity, selectivity, some cases stability. This approach proved be relevant related technologies such as fuel cell, chemical reactors organic synthesis, Therefore, this review aims critically analyze recent progress on single-atom (SACs) application oxygen reduction reaction, evolution hydrogen and/or electrochemical transformations. Finally, opportunities that may open up future summarized, along with suggesting new possible exploitation SACs.

Language: Английский

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Compressive Strain Modulation of Single Iron Sites on Helical Carbon Support Boosts Electrocatalytic Oxygen Reduction

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(42), P. 22722 - 22728

Published: Aug. 17, 2021

Abstract Designing and modulating the local structure of metal sites is key to gain unique selectivity high activity single site catalysts. Herein, we report strain engineering curved atomic iron‐nitrogen boost electrocatalytic activity. First, a helical carbon with abundant high‐curvature surface realized by carbonization polypyrrole that templated from self‐assembled chiral surfactants. The introduces compressive on supported Fe−N 4 sites. Consequently, 1.5 % compressed bonds exhibit downshifted d‐band center than planar Such change can weaken bonding strength between oxygenated intermediates sites, resulting much smaller energy barrier for oxygen reduction. Catalytic tests further demonstrate kinetic current density 7.922 mA cm −2 at 0.9 V vs. RHE obtained in alkaline media which 31 times higher ones. Our findings shed light three‐dimensional boosting catalytic via engineering.

Language: Английский

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Boosting Activity and Stability of Metal Single-Atom Catalysts via Regulation of Coordination Number and Local Composition

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(45), P. 18854 - 18858

Published: Nov. 3, 2021

Controlling the chemical environments of active metal atom including both coordination number (CN) and local composition (LC) is vital to achieve stable single-atom catalysts (SACs), but remains challenging. Here we synthesized a series supported Pt1 SACs by depositing Pt atoms onto pretuned anchoring sites on nitrogen-doped carbon using atomic layer deposition. In hydrogenation para-chloronitrobenzene, SAC with higher CN about four less pyridinic nitrogen (Npyri) content exhibits remarkably high activity along superior recyclability compared those lower CNs more Npyri. Theoretical calculations reveal that four-coordinated 1 eV formation energy are resistant agglomerations than three-coordinated ones. Composition-wise decrease Pt-Npyri bond upshifts gradually Pt-5d center, minimal one features high-lying state largely facilitates H2 dissociation, boosting remarkably.

Language: Английский

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Dispersed surface Ru ensembles on MgO(111) for catalytic ammonia decomposition

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Feb. 6, 2023

Ammonia is regarded as an energy vector for hydrogen storage, transport and utilization, which links to usage of renewable energies. However, efficient catalysts ammonia decomposition their underlying mechanism yet remain obscure. Here we report that atomically-dispersed Ru atoms on MgO support its polar (111) facets {denoted MgO(111)} show the highest rate decomposition, far are aware, than all reported in literature due strong metal-support interaction surface coupling reaction. We have carefully investigated loading effect from atomic form cluster/nanoparticle MgO(111). Progressive increase concentration, correlated with specific activity per metal site, clearly indicates synergistic sites close proximity, akin those bimetallic N

Language: Английский

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Design of Single-Atom Catalysts and Tracking Their Fate Using Operando and Advanced X-ray Spectroscopic Tools

Chemical Reviews, Journal Year: 2022, Volume and Issue: 123(1), P. 379 - 444

Published: Nov. 23, 2022

The potential of operando X-ray techniques for following the structure, fate, and active site single-atom catalysts (SACs) is highlighted with emphasis on a synergetic approach both topics. absorption spectroscopy (XAS) related have become fascinating tools to characterize solids they can be applied almost all transition metals deriving information about symmetry, oxidation state, local coordination, many more structural electronic properties. SACs, newly coined concept, recently gained much attention in field heterogeneous catalysis. In this way, one achieve minimum use metal, theoretically highest efficiency, design only site-so-called single catalysts. While sites are not easy especially under operating conditions, XAS as probe together complementary methods (infrared spectroscopy, electron microscopy) ideal research area prove structure these dynamic changes during reaction. review, starting from their fundamentals, various conventional photon in/out discussed detailed mechanistic situ/operando studies. We systematically summarize strategies SACs outline exploration supported by density functional theory (DFT) calculations recent machine learning tools.

Language: Английский

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Insights into the Mechanism of Methanol Steam Reforming Tandem Reaction over CeO₂ Supported Single-Site Catalysts

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(31), P. 12074 - 12081

Published: July 30, 2021

We demonstrated how the special synergy between a noble metal single site and neighboring oxygen vacancies provides an "ensemble reaction pool" for high hydrogen generation efficiency carbon dioxide (CO2) selectivity of tandem reaction: methanol steam reforming. Specifically, rate over Ru1/CeO2 catalyst is up to 9360 mol H2 per Ru hour (579 mLH2 gRu–1 s–1) with 99.5% CO2 selectivity. Reaction mechanism study showed that integration O facilitated reaction, which consisted dehydrogenation, water dissociation, subsequent gas shift (WGS) reaction. In addition, strength CO adsorption activation energy difference dehydrogenation WGS play important role in determining activity Our paves way further rational design catalysts at atomic scale. Furthermore, development such highly efficient selective evolution systems promises deliver desirable economic ecological benefits.

Language: Английский

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Modulating the Local Coordination Environment of Single‐Atom Catalysts for Enhanced Catalytic Performance in Hydrogen/Oxygen Evolution Reaction

Small, Journal Year: 2022, Volume and Issue: 18(17)

Published: Jan. 31, 2022

Abstract Single‐atom catalysts (SACs) hold the promise of utilizing 100% participating atoms in a reaction as active catalytic sites, achieving remarkable boost efficiency. Thus, they present great potential for noble metal‐based electrochemical application systems, such water electrolyzers and fuel cells. However, their practical applications are severely hindered by intrinsic complications, namely atom agglomeration relocation, originating from uncontrollably high surface energy isolated single‐atoms (SAs) during postsynthetic treatment processes or reactions. Extensive efforts have been made to develop new methodologies strengthening interactions between SAs supports, which could ensure desired stability sites full utilization SACs. This review covers recent progress SACs development while emphasizing association regulation coordination environments (e.g., atoms, numbers, structures) electrocatalytic performance hydrogen evolution (HER) oxygen (OER). The crucial role chemistry modifying properties manipulating metal‐loading, stability, is elucidated. Finally, future challenges SACS industrial outlook this field discussed.

Language: Английский

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