Recent advances in oxidative degradation of plastics DOI Creative Commons
Sewon Oh, Erin E. Stache

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(14), P. 7309 - 7327

Published: Jan. 1, 2024

Oxidative degradation is a powerful method to degrade plastics into oligomers and small oxidized products. While thermal energy has been conventionally employed as an external stimulus, recent advances in photochemistry have enabled photocatalytic oxidative of polymers under mild conditions. This tutorial review presents overview degradation, from its earliest examples emerging strategies. briefly discusses the motivation development with focus on underlying mechanisms. Then, we will examine modern studies primarily relevant catalytic degradation. Lastly, highlight some unique using unconventional approaches for polymer such electrochemistry.

Language: Английский

Ligand‐to‐Metal Charge Transfer (LMCT) Photochemistry at 3d‐Metal Complexes: An Emerging Tool for Sustainable Organic Synthesis DOI Creative Commons
Fabio Juliá

ChemCatChem, Journal Year: 2022, Volume and Issue: 14(19)

Published: Aug. 11, 2022

Abstract Despite the rich photochemistry of 3d‐metal complexes, utilization excited‐state reactivity these compounds in organic synthesis has been historically overlooked. The advent photoredox catalysis changed perception synthetic chemists towards photochemistry, and nowadays potential photoinduced, outer‐sphere single‐electron transfer events is widely recognized. More recently, an emerging new mode photoactivation taken spotlight, based on inner‐sphere triggered by population ligand‐to‐metal charge‐transfer (LMCT) excited states. Contrarily to photoredox, LMCT‐activation does not rely matching redox potentials, offers unique profiles particularly well suited Earth‐abundant metal complexes. Those appealing features are propelling development methods using this blueprint generate highly reactive open‐shell species under mild conditions. aim contribution provide a didactical tool for comprehension concept facilitate methodologies achieve sustainable chemical transformations.

Language: Английский

Citations

225
Catalytic oxidation of polystyrene to aromatic oxygenates over a graphitic carbon nitride catalyst DOI Creative Commons
Ruochen Cao, Meiqi Zhang, Chaoquan Hu

et al.

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Aug. 16, 2022

The continuous increase in manufacturing coupled with the difficulty of recycling plastic products has generated huge amounts waste plastics. Most existing chemical and upcycling methods suffer from harsh conditions poor product selectivity. Here we demonstrate a photocatalytic method to oxidize polystyrene aromatic oxygenates under visible light irradiation using heterogeneous graphitic carbon nitride catalysts. Benzoic acid, acetophenone, benzaldehyde are dominant liquid phase when conversion reaches >90% at 150 °C. For transformation 0.5 g waste, 0.36 is obtained. reaction mechanism also investigated various characterization procedes via activation form hydroxyl carbonyl groups over its backbone C-H bond oxidation which followed by oxidative breakage C-C further processes oxygenates.

Language: Английский

Citations

148
Biological Degradation of Plastics and Microplastics: A Recent Perspective on Associated Mechanisms and Influencing Factors DOI Creative Commons

Zeming Cai,

Minqian Li,

Ziying Zhu

et al.

Microorganisms, Journal Year: 2023, Volume and Issue: 11(7), P. 1661 - 1661

Published: June 26, 2023

Plastic and microplastic pollution has caused a great deal of ecological problems because its persistence potential adverse effects on human health. The degradation plastics through biological processes is significance for health, therefore, the feasibility plastic by microorganisms attracted lot attention. This study comprises preliminary discussion biodegradation mechanism advantages roles different bacterial enzymes, such as PET hydrolase PCL-cutinase, in polymers, PCL, respectively. With particular focus their modes action enzymatic mechanisms, this review sums up studies microplastics related to mechanisms influencing factors, along with enzymes enhancing synthetic process. In addition, also affected additives plasticizers. Plasticizers composition can cause harmful impacts. To further improve efficiency various pretreatments biodegradation, which significant reduction toxic pollution, were preliminarily discussed here. existing research data show large number involved though specific have not been thoroughly explored yet. Therefore, there employing strains efficient health safety.

Language: Английский

Citations

139
Catalytic strategies for upvaluing plastic wastes DOI Creative Commons
Meiqi Zhang, Meng Wang, Bo Sun

et al.

Chem, Journal Year: 2022, Volume and Issue: 8(11), P. 2912 - 2923

Published: Sept. 7, 2022

Language: Английский

Citations

119
Bridging Plastic Recycling and Organic Catalysis: Photocatalytic Deconstruction of Polystyrene via a C–H Oxidation Pathway DOI Creative Commons
Tengfei Li,

Arjun Vijeta,

Carla Casadevall

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(14), P. 8155 - 8163

Published: June 23, 2022

Chemical recycling of synthetic polymers represents a promising strategy to deconstruct plastic waste and make valuable products. Inspired by small-molecule C-H bond activation, visible-light-driven reaction is developed polystyrene (PS) into ∼40% benzoic acid as well ∼20% other monomeric aromatic products at 50 °C ambient pressure. The practicality this demonstrated deconstruction real-world PS foam on gram scale. proposed proceed via oxidation pathway, which supported theoretical calculations experimental results. Fluorescence quenching experiments also support efficient electron transfer between the photocatalyst polymer substrate, providing further evidence for mechanism. This study introduces concepts from catalysis provides method tackle global crisis pollution.

Language: Английский

Citations

113
Plastic Waste Valorization by Leveraging Multidisciplinary Catalytic Technologies DOI
Hua Zhou, Ye Wang, Yue Ren

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(15), P. 9307 - 9324

Published: July 18, 2022

Plastic waste triggers a series of concerns because its disruptive impact on the environment and ecosystem. From point view catalysis, however, end-of-life plastics can be seen as an untapped feedstock for preparation value-added products. Thus, development diversified catalytic approaches valorization is urgent. Previous reviews this field have systematically summarized progress made plastic reclamation. In review, we emphasize design processes by leveraging state-of-the-art technologies from other developed fields to derive valuable polymers, functional materials, chemicals plastics. The principles, mechanisms, opportunities chemical (thermo-, electro-, photocatalytic) well biocatalytic ones are discussed, which may provide more insights future processes. Finally, outlooks perspectives accelerate toward feasible economy discussed.

Language: Английский

Citations

105
Reversed Controlled Polymerization (RCP): Depolymerization from Well-Defined Polymers to Monomers DOI Creative Commons
Glen R. Jones, Hyun Suk Wang, Kostas Parkatzidis

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(18), P. 9898 - 9915

Published: May 1, 2023

Controlled polymerization methods are well-established synthetic protocols for the design and preparation of polymeric materials with a high degree precision over molar mass architecture. Exciting recent work has shown that end-group fidelity and/or functionality inherent in these techniques can enable new routes to depolymerization under relatively mild conditions. Converting polymers back pure monomers by is potential solution environmental ecological concerns associated ultimate fate polymers. This perspective focuses on emerging field from synthesized controlled polymerizations including radical, ionic, metathesis polymerizations. We provide critical review current literature categorized according technique explore numerous concepts ideas which could be implemented further enhance lower temperature systems, catalytic depolymerization, increasing polymer scope, depolymerization.

Language: Английский

Citations

103
Integrated strategy for the synthesis of aromatic building blocks via upcycling of real-life plastic wastes DOI Creative Commons
Yuman Qin, Tong Zhang,

H.Y. Vincent Ching

et al.

Chem, Journal Year: 2022, Volume and Issue: 8(9), P. 2472 - 2484

Published: June 21, 2022

Language: Английский

Citations

78
Co-upcycling of polyvinyl chloride and polyesters DOI
Ruochen Cao, Meiqi Zhang,

Yuchen Jiao

et al.

Nature Sustainability, Journal Year: 2023, Volume and Issue: 6(12), P. 1685 - 1692

Published: Oct. 9, 2023

Language: Английский

Citations

73
Identification of Alkoxy Radicals as Hydrogen Atom Transfer Agents in Ce-Catalyzed C–H Functionalization DOI
Qing An, Yang‐Yang Xing, Ruihua Pu

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 145(1), P. 359 - 376

Published: Dec. 20, 2022

The intermediacy of alkoxy radicals in cerium-catalyzed C–H functionalization via H-atom abstraction has been unambiguously confirmed. Catalytically relevant Ce(IV)–alkoxide complexes have synthesized and characterized by X-ray diffraction. Operando electron paramagnetic resonance transient absorption spectroscopy experiments on isolated pentachloro Ce(IV) alkoxides identified as the sole heteroatom-centered radical species generated ligand-to-metal charge transfer (LMCT) excitation. Alkoxy-radical-mediated hydrogen atom (HAT) verified kinetic analysis, density functional theory (DFT) calculations, reactions under strictly chloride-free conditions. These experimental findings establish critical role Ce-LMCT catalysis definitively preclude involvement chlorine radical. This study also reinforced necessity a high relative ratio alcohol vs Ce for selective alkoxy-radical-mediated HAT, seemingly trivial changes can lead to drastically different mechanistic pathways. Importantly, previously proposed radical–alcohol complex, postulated explain alkoxy-radical-enabled selectivities this system, examined scrutiny ruled out regioselectivity studies, experiments, high-level calculations. Moreover, peculiar selectivity generation LMCT homolysis heteroleptic analyzed back-electron (BET) may regulated efficiency formation ligand-centered radicals.

Language: Английский

Citations

72