Covalent Immobilization of Polyoxotungstate on Alumina and Its Catalytic Generation of Sulfoxides

Hong, Lanlan; Win, Pyaesone; Zhang, Xuan; Chen, Wei; Miras, Haralampos N.; Song, Yu‐Fei

doi:10.1002/chem.201601864

Cited by 23 publications

(29 citation statements)

References 51 publications

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“…In addition, XPS peaks of W 4 f (Fig. 3E) for K-PW 11 and 3DOM g-C 3 N 4 -PW 11 can be fitted with two peaks at binding energies of around 34.9 and 37.1 eV (W 4 f 7/2 and W 4f 5/2 ), which are consistent with a W(VI) oxidation state [13]. The P 2p and W 4f XPS results reveal that the primary structure of PW 11 cluster has been well preserved after covalent combination.…”

Section: Figmentioning

confidence: 74%

“…The similar signals at around −13.7 and −13.4 ppm of the 31 P MAS NMR for K-PW 11 and 3DOM g-C 3 N 4 -PW 11 ( Fig. 2C) reveal that the primary structure of PW 11 cluster has been well preserved after covalent combination [13]. More characterization should be performed to investigate the structure and composition of 3DOM g-C 3 N 4 -PW 11 .…”

Section: Characterization Of 3dom G-c 3 N 4 -Pw 11mentioning

confidence: 76%

“…8B shows the catalytic performance is almost unchanged and the catalyst recovery can reach above 96% even after five times. The XRD, IR, 13 C, 29 Si and 31 P MAS NMR spectra of the fresh and used 3DOM g-C 3 N 4 -PW 11 exhibits almost the same typical peaks (Figs. S11, S18 and S19).…”

Section: Recycle Of Heterogeneous 3dom G-c 3 N 4 -Pw 11mentioning

confidence: 80%

“…These advantages make POMs the ideal guest molecules for g-C 3 N 4 host. Although POMs have been combined with g-C 3 N 4 [12], these hybrid materials based on the weak interaction such as electrostatic interaction and metal-ligand coordination suffer from stability issues owning to POMs leaching [13]. Therefore, the development of covalent combining POMs with g-C 3 N 4 to enhance the interaction between them is highly desirable.…”

Section: Introductionmentioning

confidence: 99%

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Covalent combination of polyoxometalate and graphitic carbon nitride for light-driven hydrogen peroxide production

et al. 2017

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A B S T R A C TThe polyoxometalate (POM) cluster of [PW 11 O 39 ] 7-(PW 11 ) has been successfully covalent combined with the three dimensionally ordered macroporous graphitic carbon nitride (3DOM g-C 3 N 4 ) through the organic linker strategy. The characterization such as solid-state NMR and XPS results confirm the organosilicon agent of (triethoxysilyl)-propyl isocyanate can act as the linker to covalent combine the PW 11 cluster with 3DOM g-C 3 N 4 . The hybrid catalyst of 3DOM g-C 3 N 4 -PW 11 exhibits efficient catalytic performance (2.4 μmol h −1 ) for lightdriven H 2 O 2 production from H 2 O and O 2 in the absence of organic electron donors. The ESR results suggest that one-electron reduction of O 2 to •OOH is indeed suppressed over 3DOM g-C 3 N 4 -PW 11 . Furthermore, the Koutecky-Levich plot obtained from electrochemical rotating disk electrode (RDE) analysis of oxygen reduction reaction (ORR) for 3DOM g-C 3 N 4 -PW 11 reveals the value of electron transfer during the ORR process is 2.30, indicating the covalent combination can promote the two-electron O 2 reduction. In addition, the recycle experiment results reveal that the heterogeneous 3DOM g-C 3 N 4 -PW 11 is catalytic stable.

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Section: Figmentioning

confidence: 74%

Section: Characterization Of 3dom G-c 3 N 4 -Pw 11mentioning

confidence: 76%

Section: Recycle Of Heterogeneous 3dom G-c 3 N 4 -Pw 11mentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

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Covalent combination of polyoxometalate and graphitic carbon nitride for light-driven hydrogen peroxide production

et al. 2017

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“…The oxidative transformations of organic compounds under mild conditions are of great importance in industrial processes and synthetic organic chemistry . The selective oxidation of sulfides to sulfoxides and sulfones is pivotal because of its use in the chemical industry, medicinal chemistry and biology . In this work, we aim to explore the efficiency of different catalysts for the selective oxidative of thioanisole in the presence of different substrates and H 2 O 2 (Scheme ).…”

Section: Resultsmentioning

confidence: 99%

Modular Polyoxometalate–Layered Double Hydroxides as Efficient Heterogeneous Sulfoxidation and Epoxidation Catalysts

Zhang

Chen

et al. 2017

ChemCatChem

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The selective sulfoxidation of sulfides and the epoxidation of olefins are two types of important organic reactions, and the corresponding products of sulfoxides, sulfones and epoxides are used widely as raw materials in industrial processes. The fabrication of one efficient catalyst for both reactions remains a challenging task. We report the preparation of a highly efficient heterogeneous catalyst Mg3Al‐ILs‐La(PW11)2 using an exfoliation/assembly approach. The catalyst was characterised by FT‐IR spectroscopy, XRD, thermogravimetric and differential thermal analysis, BET measurements, X‐ray photoelectron spectroscopy, 29Si cross‐polarisation magic‐angle spinning NMR spectroscopy, 27Al magic‐angle spinning NMR spectroscopy, SEM, high‐resolution TEM, and energy‐dispersive X‐ray spectroscopy. The designed catalyst showed a high efficiency and selectivity for the sulfoxidation of sulfides and the epoxidation of olefins under mild conditions at a production rate of 208 and 31 mmol g−1 h−1, respectively. Moreover, Mg3Al‐ILs‐La(PW11)2 can be recycled and re‐used at least five times without a clear decrease of its catalytic activity. The scaled‐up experiments revealed that the catalyst retained its efficiency and robustness, which demonstrates the great potential of the catalyst for industrial applications.

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Polyoxometalates on Functional Substrates: Concepts, Synergies, and Future Perspectives

et al. 2020

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POMs were studied as heterogeneous acid catalysts and oxidation catalysts. However, this approach is often affected by low specific surface areas, leading to reduced reactivity. [10] Later studies, therefore, pioneered the immobilization of POMs on high surfacearea substrates including porous silica and other metal oxides, [10] as well as more advanced materials such as carbon nanostructures [11] and metal-organic frameworks (MOFs). [9] This strategy can enable maximized exposure of the individual POM molecules to the reaction environment, and in addition, allows for facile separation by filtration or centrifugation. [12] While early studies on POM immobilization used heterogeneous supports for mechanical stabilization and maximized surface-area, more recent studies have moved toward added properties introduced by the support. These include light-absorption and charge transport by semiconductors (TiO 2 , CdSe, etc.), electrical conductivity (by carbons, metals, conductive polymers) as well as specific POM binding sites, as introduced in MOFs and organofunctionalized supports. Many contemporary studies in this field share a common interest in exploring the synergism between POM and substrate to tune and optimize reactivity and stability of the composite. The concept has been theoretically and experimentally described several decades ago as the so-called "microenvironment effect" (electronic charge enhancement) where entrapment of POM species in a 3D matrix has been shown to induce huge improvement of their electrocatalytic activity. [13][14][15] However, to-date, the understanding of the fundamental processes which govern synergism of POM-substrate interactions is still in its infancy, as mole cular-level understanding of these complex processes by experiment or theory is far from trivial. This is due to the vast number of materials combinations, which are currently studied, and is further complicated by the often unknown chemical structures of the POM-substrate interface which make theoretical studies difficult. Also, in situ/operando studies of these materials are still challenging, and instrumentational approaches to address these issues are still being developed and not widely available. Most current experimental studies, therefore, focus on macroscopic reactivity, while providing less insight into the underlying causes of the processes observed.This Progress Report aims at raising awareness of the vast benefits of exploring this under-researched area to enable full use of POM-substrate interactions including charge and energy transfer, band-gap, and frontier orbital alignment as well as interface design for stability and reactivity. These fundamental concepts can affect both the thermodynamics as well as the kinetics of the chemical processes studied so that new reactivity can be tailored by understanding of the interactions between POM and substrate. Given the fast-paced progress in the synthesis, application, and characterization of this materials class, this Progress Report will serve as a focal point for ...

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Covalent Immobilization of Polyoxotungstate on Alumina and Its Catalytic Generation of Sulfoxides

Cited by 23 publications

References 51 publications

Covalent combination of polyoxometalate and graphitic carbon nitride for light-driven hydrogen peroxide production

Covalent combination of polyoxometalate and graphitic carbon nitride for light-driven hydrogen peroxide production

Modular Polyoxometalate–Layered Double Hydroxides as Efficient Heterogeneous Sulfoxidation and Epoxidation Catalysts

Polyoxometalates on Functional Substrates: Concepts, Synergies, and Future Perspectives

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