Multifunctional carbon nitride nanoarchitectures for catalysis

Chemical Society Reviews, Год журнала: 2023, Номер 52(21), С. 7602 - 7664

Опубликована: Янв. 1, 2023

Carbon nitrides, with feasibility of tailored band gap via suitable nanoarchitectonics, are deemed as best catalysts amongst existing materials, especially for HER, OWS, COR, NRR, water oxidation, pollutant removal, and organocatalysis.

Язык: Английский

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Modeling Single‐Atom Catalysis

Advanced Materials, Год журнала: 2023, Номер 35(46)

Опубликована: Сен. 25, 2023

Electronic structure calculations represent an essential complement of experiments to characterize single-atom catalysts (SACs), consisting isolated metal atoms stabilized on a support, but also predict new catalysts. However, simulating SACs with quantum chemistry approaches is not as simple often assumed. In this work, the factors that reliable simulation activity are examined. The Perspective focuses importance precise atomistic characterization active site, since even small changes in atom's surroundings can result large reactivity. dynamical behavior and stability under working conditions, well adopting appropriate methods solve Schrödinger equation for quantitative evaluation reaction energies addressed. relevance model adopted. For electrocatalysis must include effects solvent, presence electrolytes, pH, external potential. Finally, it discussed how similarities between coordination compounds may intermediates usually observed electrodes. When these aspects adequately considered, predictive power electronic quite limited.

Язык: Английский

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Single‐Atom Iron Catalyst as an Advanced Redox Mediator for Anodic Oxidation of Organic Electrosynthesis

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(27)

Опубликована: Апрель 23, 2024

Homogeneous electrocatalysts can indirect oxidate the high overpotential substrates through single-electron transfer on electrode surface, enabling efficient operation of organic electrosynthesis catalytic cycles. However, problems this chemistry still exist such as dosage, difficult recovery, and low efficiency. Single-atom catalysts (SACs) exhibit atom utilization excellent activity, hold great promise in addressing limitations homogeneous catalysts. In view this, we have employed Fe-SA@NC an advanced redox mediator to try change situation. was synthesized using encapsulation-pyrolysis method, it demonstrated remarkable performance a range reported reactions, construction various C-C/C-X bonds. Moreover, potential exploring new synthetic method for electrosynthesis. We develop electro-oxidative ring-opening transformation cyclopropyl amides. reaction system, showed good tolerance drug molecules with complex structures, well flow electrochemical syntheses gram-scale transformations. This work highlights SACs electrosynthesis, thereby opening avenue chemistry.

Язык: Английский

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Fabricating a Structured Single‐Atom Catalyst via High‐Resolution Photopolymerization 3D Printing

Advanced Functional Materials, Год журнала: 2024, Номер unknown

Опубликована: Апрель 29, 2024

Abstract This study introduces a novel solution to the design of structured catalysts, integrating single‐piece 3D printing with single‐atom catalysis. Structured catalysts are widely employed in industrial processes, as they provide optimal mass and heat transfer, leading more efficient use catalytic materials. They conventionally prepared using ceramic or metallic bodies, which then washcoated impregnated catalytically active layers. However, this approach may lead adhesion issues latter. By employing photopolymerization printing, stable catalyst is directly shaped into stand‐alone, material. The battery characterization methods present confirms uniform distribution species structural integrity Computational fluid dynamics simulations applied demonstrate enhanced momentum transfer light within body. materials finally evaluated continuous‐flow photocatalytic oxidation benzyl alcohol benzaldehyde, relevant reaction prepare biomass‐derived building blocks. innovative reported herein manufacture circumvents complexities traditional synthetic methods, offering scalability efficiency improvements, highlights transformative role catalysis engineering revolutionize catalysts’ design.

Язык: Английский

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Resolving the Nanostructure of Carbon Nitride‐Supported Single‐Atom Catalysts

Small, Год журнала: 2025, Номер unknown

Опубликована: Янв. 9, 2025

Abstract Single‐atom catalysts (SACs) are gathering significant attention in chemistry due to their unique properties, offering uniform active site distribution and enhanced selectivity. However, precise structure often remains unclear, with multiple models proposed the literature. Understanding coordination environment of at atomic level is crucial for explaining catalytic activity. Here, a comprehensive study SACs made carbon nitride (CN x ) containing isolated nickel atoms presented. Using combination synthesis techniques characterization methods including Fourier‐transform infrared spectroscopy, X‐ray absorption spectroscopy (XAS), density functional theory (DFT) calculations, local centers CN ‐supported investigated. These results challenge conventional structural propose new architecture that better aligns current experimental evidence. This serves as foundational step toward rational approach catalyst development can facilitate more design application these innovative catalysts.

Язык: Английский

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Enhanced Three-Component Chloro-/Azido-Fluoroalkylation of Unactivated Alkenes via the Proximity Effect in a Heterogenous Metallaphotocatalyst

ACS Catalysis, Год журнала: 2025, Номер 15(3), С. 2180 - 2191

Опубликована: Янв. 22, 2025

Heterogeneous metallaphotocatalytic chemical transformations employing a recyclable catalyst are highly desirable for organic synthesis. However, the rational design and controlled preparation of well-defined, site-isolated metal/photo bifunctional heterogeneous catalysts to achieve this goal remain significant challenge. In study, we demonstrate covalent attachment homogeneous molecular MnSalen complex (where Salen = N,N′-bis(salicylidene)ethylenediamine) onto surface graphitic carbon nitride (CN) via an amide bond visible-light-driven chloro- azido-fluoroalkylation unactivated alkenes. The linkage between CN not only facilitates electron delocalization enhances light-harvesting capabilities photosensitizer but also exerts proximity effect that markedly ability Mn sites capture alkyl radical intermediates during reaction process. A diverse set alkenes could be efficiently azido-fluoroalkylated their corresponding difunctionalized products in moderate high yields with good functional group compatibility. Furthermore, practicability protocol is illustrated through late-stage diversification various bioactive compounds pharmaceuticals. Notably, integrated photocatalyst demonstrates stability can recycled at least 10 times without loss activity selectivity.

Язык: Английский

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Integrative catalytic pairs for efficient multi-intermediate catalysis

Nature Nanotechnology, Год журнала: 2024, Номер 19(10), С. 1442 - 1451

Опубликована: Авг. 5, 2024

Язык: Английский

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Hidden Impurities Generate False Positives in Single Atom Catalyst Imaging

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(44)

Опубликована: Май 15, 2024

Single-atom catalysts (SACs) are an emerging class of materials, leveraging maximum atom utilization and distinctive structural electronic properties to bridge heterogeneous homogeneous catalysis. Direct imaging methods, such as aberration-corrected high-angle annular dark-field scanning transmission electron microscopy, commonly applied confirm the atomic dispersion active sites. However, interpretations data from these techniques can be challenging due simultaneous contributions intensity impurities introduced during synthesis processes, well any variation in position relative focal plane beam. To address this matter, paper presents a comprehensive study on two representative SACs containing isolated nickel or copper atoms. Spectroscopic techniques, including X-ray absorption spectroscopy, were employed prove high metal catalytic Employing microscopy combined with single-atom-sensitive energy loss we scrutinized thin specimens provide unambiguous chemical identification observed single-atom species thereby distinguish sites at level. Overall, underscores complexity characterization establishes importance use spectroscopy tandem resolution fully reliably characterize catalysts.

Язык: Английский

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Feeble Single-Atom Pd Catalysts for H₂ Production from Formic Acid

ACS Applied Materials & Interfaces, Год журнала: 2024, Номер 16(8), С. 10251 - 10259

Опубликована: Янв. 19, 2024

Single-atom catalysts are thought to be the pinnacle of catalysis. However, for many reactions, their suitability has yet unequivocally proven. Here, we demonstrate why single Pd atoms (PdSA) not catalytically ideal generating H2 from formic acid as a carrier. We loaded PdSA on three silica substrates, mesoporous silicas functionalized with thiol, amine, and dithiocarbamate functional groups. The catalytic activity amino-functionalized (SiO2–NH2/PdSA) was far higher than that thiol-based (SiO2–S–PdSA SiO2–NHCS2–PdSA), while single-atom stability SiO2–NH2/PdSA against aggregation after first cycle weakest. In this case, boosted reaction yield. Our experiments calculations in loosely binds amine This leads limited charge transfer groups causes high aggregability activity. According density calculations, loose binding between N most Pd's 4d electrons SiO2 remain close Fermi level labile chemically thiol group, resulting strong hybridization S, pulling states deeper into conduction band away level. Consequently, fewer were available

Язык: Английский

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Multicomponent Reductive Coupling for Selective Access to Functional γ-Lactams by a Single-Atom Cobalt Catalyst

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Март 21, 2024

Despite their significant importance to numerous fields, the difficulties in direct and diverse synthesis of α-hydroxy-γ-lactams pose substantial obstacles practical applications. Here, we designed a nitrogen TiO2 co-doped graphitic carbon-supported material with atomically dispersed cobalt sites (CoSA-N/NC-TiO2), which was successfully applied as multifunctional catalyst establish general method for construction from cheap abundant nitro(hetero)arenes, aldehydes, H2O alkynoates. The striking features operational simplicity, broad substrate functionality compatibility (>100 examples), high step atom efficiency, good selectivity, exceptional reusability highlight practicality this new catalytic transformation. Mechanistic studies reveal that active CoN4 species dopants exhibit synergistic effect on formation key acid-masked nitrones; subsequent nucleophilic addition alkynoates followed by successive reduction, alkenyl hydration, intramolecular ester ammonolysis delivers desired products. In work, concept reduction interruption leading reaction route will open door further develop useful transformations rational design.

Язык: Английский

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