Metal–Organic Framework-Based Catalysts with Single Metal Sites

Chemical Reviews, Journal Year: 2020, Volume and Issue: 120(21), P. 12089 - 12174

Published: May 1, 2020

Metal-organic frameworks (MOFs) are a class of distinctive porous crystalline materials constructed by metal ions/clusters and organic linkers. Owing to their structural diversity, functional adjustability, high surface area, different types MOF-based single sites well exploited, including coordinately unsaturated from nodes metallolinkers, as active species immobilized MOFs. Furthermore, controllable thermal transformation MOFs can upgrade them nanomaterials functionalized with single-atom catalysts (SACs). These unique features derivatives enable serve highly versatile platform for catalysis, which has actually been becoming rapidly developing interdisciplinary research area. In this review, we overview the recent developments catalysis at in emphasis on structures applications thermocatalysis, electrocatalysis, photocatalysis. We also compare results summarize major insights gained works providing challenges prospects emerging field.

Language: Английский

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Synthesis of micro/nanoscaled metal–organic frameworks and their direct electrochemical applications

Chemical Society Reviews, Journal Year: 2019, Volume and Issue: 49(1), P. 301 - 331

Published: Dec. 13, 2019

As a new class of crystalline porous materials, metal-organic frameworks (MOFs) have received great attention owing to their unique advantages ultrahigh surface area, large pore volume and versatile applications. Developing different strategies control the morphology size MOFs is very important for practical Recently, micro/nanosized been regarded as promising candidates electrode materials with excellent performances, which not only bridge gap between fundamental MOF science forward-looking applications, but also provide an opportunity make clear relationship morphologies properties. This review focuses on design fabrication one-, two- three-dimensional at micro/nanoscale, direct applications in batteries, supercapacitors electrocatalysis. A discussion challenges future prospects synthesis electrochemical micro/nanoscaled presented.

Language: Английский

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Z‐Scheme Photocatalytic Systems for Carbon Dioxide Reduction: Where Are We Now?

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(51), P. 22894 - 22915

Published: Feb. 3, 2020

Transforming CO2 into fuels by utilizing sunlight is promising to synchronously overcome global warming and energy-supply issues. It crucial design efficient photocatalysts with intriguing features such as robust light-harvesting ability, strong redox potential, high charge-separation, excellent durability. Hitherto, a single-component photocatalyst incapable simultaneously meet all these criteria. Inspired natural photosynthesis, constructing artificial Z-scheme provides facile way conquer bottlenecks. In this review, we firstly introduce the fundamentals of photocatalytic reduction systems. Thereafter discuss state-of-the-art reduction, whereby special attention placed on predominant factors that affect photoactivity. Additionally, further modifications are important for photocatalysis reviewed.

Language: Английский

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Defect Engineering in Photocatalytic Nitrogen Fixation

ACS Catalysis, Journal Year: 2019, Volume and Issue: 9(11), P. 9739 - 9750

Published: Sept. 17, 2019

Approximately 2% of the energy consumed by humans each year is used to make nitrogen-based fertilizers, with ammonia (NH3) production being most significant contributor this demand. Currently, NH3 synthesized Haber–Bosch process, an energy-intensive synthesis requiring both high temperatures (400–500 °C) and pressures (150–250 atm) achieve meaningful rates N2 conversion. As a means reducing input carbon footprint synthesis, researchers are now seeking more environmentally friendly approaches for fixation. Photocatalytic using sunlight semiconductor photocatalyst, represents one promising strategies (typically employing water as agent). Rates photocatalytic currently too low justify serious practical consideration, which can be traced sluggish adsorption/activation kinetics molecule on catalyst surfaces under ambient temperature pressure conditions. Recent studies have highlighted potential defect engineering boosting light-harvesting, charge separation, adsorption characteristics photocatalysts in reductive processes such splitting CO2 reduction. Herein, we explore similarly enhance Special emphasis placed structure modulation (especially 2D materials porous structures) interface (including vacancy creation, metal doping, strain) enhancing activation The overarching aim Perspective provide snapshot recent breakthroughs rational design thus providing useful scaffold future research very exciting emerging field.

Language: Английский

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Rational Catalyst Design for N₂ Reduction under Ambient Conditions: Strategies toward Enhanced Conversion Efficiency

ACS Catalysis, Journal Year: 2020, Volume and Issue: 10(12), P. 6870 - 6899

Published: May 26, 2020

Ammonia (NH3), one of the basic chemicals in most fertilizers and a promising carbon-free energy storage carrier, is typically synthesized via Haber–Bosch process with high consumption massive emission greenhouse gases. The photo/electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions has attracted increasing interests recently, providing alternative routes to realize green NH3 synthesis. Despite rapid advances achieved this attractive research field, unsatisfactory conversion efficiency including low yield rate, limited Faradaic or apparent quantum still remains as great challenge. NRR performance intrinsically related electronic surface structure catalysts. Rational design preparation advanced catalysts are indispensable improve (e.g., activity selectivity) NRR. In Review, various strategies for development desirable comprehensively summarized, mainly containing defect engineering, structural manipulation, crystallographic tailoring, interface regulation. State-of-the-art heterogeneous catalysts, prevailing theories underlying catalytic mechanisms, together current issues, critical challenges, perspectives discussed. It highly expected that Review will promote understanding recent area stimulate greater designing future.

Language: Английский

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Recent progress in first row transition metal Layered double hydroxide (LDH) based electrocatalysts towards water splitting: A review with insights on synthesis

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 469, P. 214666 - 214666

Published: July 1, 2022

Language: Английский

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Recent Advances in Noncontact External-Field-Assisted Photocatalysis: From Fundamentals to Applications

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(8), P. 4739 - 4769

Published: April 5, 2021

The effective separation of photogenerated carriers plays a vital role in photocatalytic reactions. In addition to the intrinsic driving force photocatalysis, an external field generating enhancement effect can provide extra energy system, acting as additional impetus separate charges and thus improving overall catalytic efficiency. Under favorable noncontact conditions, exploring field, different from pure photocatalysis or photoelectrocatalysis, could widen applications technology. this review, four typical fields (i.e., thermal, magnetic, microwave, ultrasonic fields) their coupling effects on are summarized. Specifically, review focuses mechanism characteristics each field's synergistic performance system. charge forces provided by traditional one distinguished defined for first time. challenges future prospects external-field-driven discussed. We hope that will reference research development external-field-assisted give insights in-depth study external-field-coupling-enhanced toward improvement

Language: Английский

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Emerging Materials and Methods toward Ammonia‐Based Energy Storage and Conversion

Advanced Materials, Journal Year: 2021, Volume and Issue: 33(50)

Published: April 8, 2021

Abstract Efficient storage and conversion of renewable energies is critical importance to the sustainable growth human society. With its distinguishing features high hydrogen content, energy density, facile storage/transportation, zero‐carbon emission, ammonia has been recently considered as a promising carrier for long‐term large‐scale storage. Under this scenario, synthesis, storage, utilization are key components implementation ammonia‐mediated system. Being different from fossil fuels, normally have intermittent variable nature, thus pose demands on improvement existing technologies simultaneously development alternative methods materials synthesis The release in an efficient manner, other hand, vital achieve supply complete nitrogen circle. Herein, recent advances thermal‐, electro‐, plasma‐, photocatalytic or separation, thermal/electrochemical decomposition summarized with emphasis latest developments new (catalysts, electrodes, sorbents) these processes. challenges potential solutions discussed.

Language: Английский

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Alkali Etching of Layered Double Hydroxide Nanosheets for Enhanced Photocatalytic N₂ Reduction to NH₃

Advanced Energy Materials, Journal Year: 2020, Volume and Issue: 10(34)

Published: July 26, 2020

Abstract Layered double hydroxide (LDH) nanosheets show good activity in a wide range of photoreactions, with this being generally attributable to an abundance surface oxygen vacancies or coordinatively unsaturated metal cations the which serve as active sites for reactant adsorption and activation. Recently, LDH have been shown be very effective photocatalytic N 2 reduction NH 3 using water reducing agent. Herein, it is demonstrated that simple pretreatment ZnCr‐LDH, ZnAl‐LDH, NiAl‐LDH aqueous NaOH can greatly enhance concentration low coordination centers nanosheets, thus significantly enhancing their under UV–vis irradiation (without need added sacrificial agents cocatalysts). The facile alkali etching strategy introduced here expected widely adopted future development high‐performance photocatalysts ammonia production other challenging chemical transformations (e.g., CO splitting).

Language: Английский

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Efficient Photocatalytic Nitrogen Fixation over Cu^δ+‐Modified Defective ZnAl‐Layered Double Hydroxide Nanosheets

Advanced Energy Materials, Journal Year: 2020, Volume and Issue: 10(8)

Published: Jan. 15, 2020

Abstract The photocatalytic reduction of nitrogen (N 2 ) with water (H O) as the reducing agent holds great promise a sustainable future technology for synthesis ammonia (NH 3 ). Herein, effect oxygen vacancies and electron‐rich Cu δ + on performance zinc‐aluminium layered double hydroxide (ZnAl‐LDH) nanosheet photocatalysts N to NH under UV–vis excitation is systematically explored. Results show that 0.5%‐ZnAl‐LDH photocatalyst (containing 0.5 mol% by metal basis) affords remarkable production rate 110 µmol g −1 h excellent stability in pure water. X‐ray absorption spectroscopy, electron paramagnetic resonance, density functional theory calculations reveal addition imparts coordinatively unsaturated (δ < 2) property ZnAl‐LDH nanosheets, both which readily contribute efficient separation transfer photogenerated electrons holes promote adsorption, thereby activating facilitating its multielectrons .

Language: Английский

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