Oxygen Evolution/Reduction Reaction Catalysts: From In Situ Monitoring and Reaction Mechanisms to Rational Design

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(9), P. 6257 - 6358

Published: March 21, 2023

The oxygen evolution reaction (OER) and reduction (ORR) are core steps of various energy conversion storage systems. However, their sluggish kinetics, i.e., the demanding multielectron transfer processes, still render OER/ORR catalysts less efficient for practical applications. Moreover, complexity catalyst–electrolyte interface makes a comprehensive understanding intrinsic mechanisms challenging. Fortunately, recent advances in situ/operando characterization techniques have facilitated kinetic monitoring under conditions. Here we provide selected highlights mechanistic studies with main emphasis placed on heterogeneous systems (primarily discussing first-row transition metals which operate basic conditions), followed by brief outlook molecular catalysts. Key sections this review focused determination true active species, identification sites, reactive intermediates. For in-depth insights into above factors, short overview metrics accurate characterizations is provided. A combination obtained time-resolved information reliable activity data will then guide rational design new Strategies such as optimizing restructuring process well overcoming adsorption-energy scaling relations be discussed. Finally, pending current challenges prospects toward development homogeneous presented.

Language: Английский

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Carbon nitride based materials: more than just a support for single-atom catalysis

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(15), P. 4878 - 4932

Published: Jan. 1, 2023

Recently, the missing link between homogeneous and heterogeneous catalysis has been found it was named single-atom (SAC). However, SAC field still faces important challenges, one of which is controlling bonding/coordination single atoms support in order to compensate for increase surface energy when particle size reduced due atomic dispersion. Excellent candidates meet this requirement are carbon nitride (CN)-based materials. Metal can be firmly trapped nitrogen-rich coordination sites CN materials, makes them a unique class hosts preparing catalysts (SACs). As most promising two-dimensional supports stabilize isolated metal atoms, materials have increasingly employed SACs. Herein, we will cover recent advances single-atoms supported by In review, characterization techniques challenges faced topic discussed, commonly synthetic methods delineated different Finally, catalytic performance SACs based on nitrides reviewed with special focus their photocatalytic applications. particular, prove as non-innocent support. The relationship two-way, where change electronic properties support, while features matrix tune activity reactions. highlight frontiers field, including analytical method development, truly controlled methods, allowing fine control loading multi-element synthesis, how understanding two-way exchange behind push next level.

Language: Английский

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Outlook on Single Atom Catalysts for Persulfate-Based Advanced Oxidation

ACS ES&T Engineering, Journal Year: 2022, Volume and Issue: 2(10), P. 1776 - 1796

Published: Sept. 7, 2022

Single atom catalysts (SACs) have emerged as a promising catalyst material architecture for energy, chemical, and environmental applications. In the past several years, SACs been increasingly explored persulfate-based advanced oxidation processes (AOPs) due to their superior persulfate activation pollutant degradation performance compared benchmark dissolved ion nanoparticle catalysts. However, there still exist uncertainties on mechanism of by SACs, which involves complex interplay sulfate hydroxyl radicals, singlet oxygen, high-valent metal species, and/or mediated electron transfer. Questions also remain how ions molecularly align single site, are converted into reactive what design parameters lead higher efficiency degradation. this critical review, we examine SAC materials employed AOPs discuss they function differently counterparts. We further our discussion current limitations, opportunities, future research needs in (i) filling knowledge gaps mechanisms persulfate-SAC interactions; (ii) augmenting fundamental with theoretical simulation situ characterization techniques; (iii) improving tailored applications; (iv) proactively considering challenges associated engineering practices water matrixes.

Language: Английский

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Single-Atom Cu Channel and N-Vacancy Engineering Enables Efficient Charge Separation and Transfer between C₃N₄ Interlayers for Boosting Photocatalytic Hydrogen Production

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(9), P. 6280 - 6288

Published: April 21, 2023

Polymeric carbon nitride (C3N4) has attracted great attention in photocatalysis due to its low-cost, visible-light response, and environment-friendly merits. However, the catalytic efficiency of pristine bulk C3N4 is severely limited by poor photoinduced electron/hole pair separation interlayer charge transport. Herein, single-atom Cu bridged into sheet interlayers through thermal condensation self-assembly supramolecules precursors melamine–cyanuric acid monomers. Simultaneously, N vacancies are engineered only gradient temperature. The bridges serve as electron channels promote experimental results calculations demonstrate that break symmetry C3N4, allowing more electrons pass delocalized π-conjugated network sites, which facilitates transfer between layers, resulting effective pairs, optimal distribution, lower hydrogen evolution barrier. As a result, photocatalyst at stationary point with 1 wt % Pt cocatalyst presents high photocatalytic production rate (11.23 mmol g–1 h–1), reaching apparent quantum yield 31.60% 420 nm. It noted still exhibits 605.15 μmol h–1 absence cocatalyst.

Language: Английский

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Single‐Atom Catalysis in Organic Synthesis

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(34)

Published: March 15, 2023

Single-atom catalysts hold the potential to significantly impact chemical sector, pushing boundaries of catalysis in new, uncharted directions. These materials, featuring isolated metal species ligated on solid supports, can exist many coordination environments, all which have shown important functions specific transformations. Their emergence has also provided exciting opportunities for mimicking metalloenzymes and bridging gap between homogeneous heterogeneous catalysis. This Review outlines impressive progress made recent years regarding use single-atom organic synthesis. We illustrate knowledge gaps search more sustainable, earth-abundant synthetic applications.

Language: Английский

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Iron‐Based Nanocatalysts for Electrochemical Nitrate Reduction

Small Methods, Journal Year: 2022, Volume and Issue: 6(10)

Published: Sept. 14, 2022

Abstract Nitrate has a high level of stability and persistence in water, endangering human health aquatic ecosystems. Due to its reliability efficiency, the electrochemical nitrate reduction reaction (NO 3 RR) is regarded as best available option for mitigating excess water wastewater, especially removal trace levels nitrate. One most critical factors are catalysts, which directly affect efficiency removal. Iron‐based nanocatalysts, have advantages nontoxicity, wide availability, low cost, emerged promising NO RR material recent years. This review covers major aspects iron‐based nanocatalysts RR, including synthetic methods, structural design, performance enhancement, electrocatalytic test, mechanism. The progress mechanism functional modified structures reviewed from perspectives loading, doping, assembly strategies, order realize conversion pollutant harmless nitrogen or ammonia other sustainable products. Finally, challenges future directions development low‐cost highly‐efficient explored.

Language: Английский

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Rare‐Earth Single‐Atom Catalysts: A New Frontier in Photo/Electrocatalysis

Small Methods, Journal Year: 2022, Volume and Issue: 6(8)

Published: June 25, 2022

Abstract Single‐atom catalysts (SACs) provide well‐defined active sites with 100% atom utilization, and can be prepared using a wide range of support materials. Therefore, they are attracting global attention, especially in the fields energy conversion storage. To date, research has focused on transition‐metal precious‐metal‐based SACs. More recently, rare‐earth (RE)‐based SACs have emerged as new frontier photo/electrocatalysis owing to their unique electronic structure arising from spin‐orbit coupling 4f valence orbitals, unsaturated coordination environment, behavior charge‐transport bridges. However, systematic review role RE sites, catalytic mechanisms, synthetic methods for is lacking. this review, latest developments having applications summarized discussed. First, theoretical advantages briefly introduced, focusing roles orbitals coupled levels. In addition, most recent progress several important photo/electrocatalytic reactions corresponding mechanisms Further, strategies production reported. Finally, challenges development highlighted, along future directions perspectives.

Language: Английский

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Nitrogen-doped carbon-based single-atom Fe catalysts: Synthesis, properties, and applications in advanced oxidation processes

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 475, P. 214874 - 214874

Published: Oct. 15, 2022

Language: Английский

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Fundamental, application and opportunities of single atom catalysts for Li-S batteries

Energy storage materials, Journal Year: 2022, Volume and Issue: 55, P. 322 - 355

Published: Dec. 5, 2022

Language: Английский

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Single Atom Catalysts for Selective Methane Oxidation to Oxygenates

ACS Nano, Journal Year: 2022, Volume and Issue: 16(6), P. 8557 - 8618

Published: May 31, 2022

Direct conversion of methane (CH4) to C1–2 liquid oxygenates is a captivating approach lock carbons in transportable value-added chemicals, while reducing global warming. Existing approaches utilizing the transformation CH4 fuel via tandemized steam reforming and Fischer–Tropsch synthesis are energy capital intensive. Chemocatalytic partial oxidation remains challenging due negligible electron affinity, poor C–H bond polarizability, high activation barrier. Transition-metal stoichiometric catalysts harsh oxidants reaction conditions perform poorly with randomized product distribution. Paradoxically, which active enough break also promote overoxidation, resulting CO2 generation reduced carbon balance. Developing can bonds selectively make useful chemicals at mild vital commercialization. Single atom (SACs) specifically coordinated metal centers on support have displayed intrigued reactivity selectivity for oxidation. SACs significantly reduce induced electrostatic polarization facilitate accelerated rate low temperature. The distinct metal–support interaction stabilize intermediate prevent overoxidation products. present review accounts recent progress field selective oxygenates. chemical nature catalytic sites, effects interaction, stabilization species minimize thoroughly discussed forward-looking perspective improve performance.

Language: Английский

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