An Atomically Dispersed Mn-Photocatalyst for Generating Hydrogen Peroxide from Seawater via the Water Oxidation Reaction (WOR)

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(30), P. 16584 - 16596

Published: July 24, 2023

In this work, we have fabricated an aryl amino-substituted graphitic carbon nitride (g-C3N4) catalyst with atomically dispersed Mn capable of generating hydrogen peroxide (H2O2) directly from seawater. This new exhibited excellent reactivity, obtaining up to 2230 μM H2O2 in 7 h alkaline water and 1800 seawater under identical conditions. More importantly, the was quickly recovered for subsequent reuse without appreciable loss performance. Interestingly, unlike usual two-electron oxygen reduction reaction pathway, generation through a less common oxidation (WOR) process which both direct indirect WOR processes occurred; namely, photoinduced h+ oxidized H2O via one-step 2e- WOR, first hydroxide (OH-) ion generate hydroxy radical (•OH), formed indirectly by combination two •OH. We characterized material, at catalytic sites, atomic level using electron paramagnetic resonance, X-ray absorption near edge structure, extended fine high-resolution transmission microscopy, photoelectron spectroscopy, magic-angle spinning solid-state NMR multiscale molecular modeling, combining classical reactive dynamics simulations quantum chemistry calculations.

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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Heterogeneous M-N-C Catalysts for Aerobic Oxidation Reactions: Lessons from Oxygen Reduction Electrocatalysts

Chemical Reviews, Journal Year: 2022, Volume and Issue: 123(9), P. 6233 - 6256

Published: Oct. 5, 2022

Nonprecious metal heterogeneous catalysts composed of first-row transition metals incorporated into nitrogen-doped carbon matrices (M-N-Cs) have been studied for decades as leading alternatives to Pt the electrocatalytic O

Language: Английский

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Tailoring First Coordination Sphere of Dual‐Metal Atom Sites Boosts Oxygen Reduction and Evolution Activities

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(28)

Published: Feb. 24, 2024

Abstract It is important to tune the coordination configuration of dual‐atom catalyst (DAC), especially in first sphere, render high intrinsic catalytic activities for oxygen reduction/evolution reactions (ORR/OER). Herein, a type atomically dispersed and boron‐coordinated DAC structure, namely, FeN 4 B‐NiN B dual sites, reported. In this incorporation boron into sphere /NiN atomic sites regulates its geometry electronic structure by forming “Fe‐B‐N” “Ni‐B‐N” bridges. The exhibits much enhanced ORR OER property compared ‐NiN counterparts. Density functional theory calculations reveal that boron‐induced charge transfer asymmetric distributions central Fe/Ni atoms optimize adsorption desorption behavior ORR/OER intermediates reduce activation energy potential‐determining step. Zinc‐air batteries employing cathode exhibit maximum power density (236.9 mW cm −2 ) stable cyclability up 1100 h. result illustrates pivotal role first‐coordination DACs tuning electrochemical conversion storage activities.

Language: Английский

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Unprecedented Relay Catalysis of Curved Fe₁–N₄ Single-Atom Site for Remarkably Efficient ¹O₂ Generation

ACS Catalysis, Journal Year: 2022, Volume and Issue: 13(1), P. 681 - 691

Published: Dec. 23, 2022

The design of catalysts and catalytic processes for high efficiency selectivity important singlet oxygen (1O2) active species generation in oxidation reactions is still challenging, especially utilizing abundant environmental O2 without photoelectric field or extra thermal condition. Herein, a curved Fe1–N4 single-atom site developed by incorporating isolated Fe single atom into nanodiamond with high-curvature surface. It leads to an unprecedented relay catalysis route, which the activation coupled peroxymonosulfate (PMS) activation, efficiently generate 1O2 species. In detail, PMS first activated on electron donation atom, accompanied 1/2 equiv production. More importantly, due compressive strain higher energy level 3dz2 orbital, charge acquisition can directly transfer molecule consequently trigger additional 1 1O2. Taking advantage this tandem process, remarkable near 100% are achieved, ultrahigh metal 0.77 min–1 tetracycline oxidative degradation outstanding performance benzene alcohol selective oxidation. This work, one hand, opens up efficient way peroxide-based oxidations, other develops bifunctional rapid gain loss ability, sheds light further improving via mechanism.

Language: Английский

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An enzyme-mimic single Fe-N ₃ atom catalyst for the oxidative synthesis of nitriles via C─C bond cleavage strategy

Science Advances, Journal Year: 2022, Volume and Issue: 8(40)

Published: Oct. 7, 2022

The cleavage and functionalization of recalcitrant carbon─carbon bonds is highly challenging but represents a very powerful tool for value-added transformation feedstock chemicals. Here, an enzyme-mimic iron single-atom catalyst (SAC) bearing (III) nitride (FeN3) motifs was prepared found to be robust cyanation carbon-carbon in secondary alcohols ketones. High nitrile yields are obtained with wide variety functional groups. FeN3-SAC exhibits high enzyme-like activity capable generating dioxygen-to-superoxide radical at room temperature, while the commonly reported FeN4-SAC FeN4 inactive. Density theory (DFT) calculation reveals that activation energy dioxygen rate-determining step formation lower over than FeN4-SAC. In addition, DFT also explains catalyst's selectivity nitriles.

Language: Английский

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High Nitrile Yields of Aerobic Ammoxidation of Alcohols Achieved by Generating ^•O₂^– and Br^• Radicals over Iron-Modified TiO₂ Photocatalysts

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(51), P. 23321 - 23331

Published: Dec. 14, 2022

Catalytic ammoxidation of alcohols into nitriles is an essential reaction in organic synthesis. While highly desirable, conducting the synthesis at room temperature challenging, using NH3 as nitrogen source, O2 oxidant, and a catalyst without noble metals. Herein, we report robust photocatalysts consisting Fe(III)-modified titanium dioxide (Fe/TiO2) for reactions utilizing oxygen atmospheric pressure, NH4Br additive. To best our knowledge, this first example catalytic over photocatalyst such cheap benign materials. Various (hetero) aromatic were synthesized high yields, aliphatic could also be transformed corresponding considerable yields. The modification TiO2 with Fe(III) facilitates formation active •O2– radicals increases adsorption amino intermediates on catalyst, accelerating to yield nitriles. additive impressively improves efficiency via bromine (Br•) from Br–, which works synergistically capture H• Cα-H, present benzyl alcohol intermediate aldimine (RCH═NH), generate carbon-centered radicals. Further, generation Br• Br– consumes photogenerated holes OH• prevent over-oxidation, significantly improving selectivity toward This amalgamation function synergy Fe(III)-doped reveals new opportunities developing semiconductor-based photocatalytic systems fine chemical

Language: Английский

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The green chemistry paradigm in modern organic synthesis

Russian Chemical Reviews, Journal Year: 2023, Volume and Issue: 92(12), P. RCR5104 - RCR5104

Published: Dec. 1, 2023

After the appearance of green chemistry concept, which was introduced in vocabulary early 1990s, its main statements have been continuously developed and modified. Currently, there are 10–12 cornerstones that should form basis for an ideal chemical process. This review analyzes accumulated experience achievements towards design products processes reduce or eliminate use generation hazardous substances. The presents views leading Russian scientists specializing various fields this subject, including homogeneous heterogeneous catalysis, fine basic organic synthesis, electrochemistry, polymer chemistry, based on bio-renewable feedstocks energetic compounds materials. A new approach to quantitative evaluation environmental friendliness by authors is described. <br> bibliography includes 1761.

Language: Английский

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Reductive Coupling of Nitroarenes and HCHO for General Synthesis of Functional Ethane-1,2-diamines by a Cobalt Single-Atom Catalyst

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(31), P. 17329 - 17336

Published: July 7, 2023

Despite the extensive applications, selective and diverse access to N,N'-diarylethane-1,2-diamines remains, date, a challenge. Here, by developing bifunctional cobalt single-atom catalyst (CoSA-N/NC), we present general method for direct synthesis of such compounds via reductive coupling cheap abundant nitroarenes formaldehyde, featuring good substrate functionality compatibility, an easily accessible base metal with excellent reusability, high step atom efficiency. Mechanistic studies reveal that N-anchored single atoms (CoN4) serve as catalytically active sites reduction processes, N-doped carbon support enriches HCHO timely trap in situ formed hydroxyamines affords requisite nitrones under weak alkaline conditions, subsequent inverse electron demand 1,3-dipolar cycloaddition imines followed hydrodeoxygenation cycloadducts furnishes products. In this work, concept catalyst-controlled nitroarene create specific building blocks is anticipated develop more useful chemical transformations.

Language: Английский

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Modulating the coordination environment of Co single-atom catalysts through sulphur doping to efficiently enhance peroxymonosulfate activation for degradation of carbamazepine

Chemical Engineering Journal, Journal Year: 2023, Volume and Issue: 474, P. 145377 - 145377

Published: Aug. 11, 2023

Language: Английский

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