Upcycling Plastic Wastes into Value‐Added Products by Heterogeneous Catalysis

ChemSusChem, Journal Year: 2022, Volume and Issue: 15(14)

Published: April 19, 2022

Abstract Plastics are playing essential roles in the modern society. The majority of them enter environment through landfilling or discarding after turning into wastes, causing severe carbon loss and imposing high risk to ecosystem human health. Currently, physical recycling serves as primary method reuse plastic waste, but this is limited thermoplastic recycling. quality recycled plastics gradually deteriorates because undesirable degradation process. Under such background, catalytic upcycling, which can upgrade various wastes value‐added products under mild conditions, has attracted recent attention a promising strategy treat wastes. This Review highlights advances development efficient heterogeneous catalysts useful strategies for upcycling liquid hydrocarbons, arene compounds, materials, hydrogen, other chemicals. functions reaction mechanisms discussed. key factors that influence performance also analyzed.

Language: Английский

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Depolymerization within a Circular Plastics System

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(5), P. 2617 - 2650

Published: Feb. 22, 2024

The societal importance of plastics contrasts with the carelessness which they are disposed. Their superlative properties lead to economic and environmental efficiency, but linearity puts climate, human health, global ecosystems at risk. Recycling is fundamental transitioning this linear model into a more sustainable, circular economy. Among recycling technologies, chemical depolymerization offers route virgin quality recycled plastics, especially when valorizing complex waste streams poorly served by mechanical methods. However, exists in interlinked system end-of-life fates, complementarity each approach key environmental, economic, sustainability. This review explores recent progress made five commercial polymers: poly(ethylene terephthalate), polycarbonates, polyamides, aliphatic polyesters, polyurethanes. Attention paid not only catalytic technologies used enhance efficiencies also interrelationship other systemic constraints imposed Novel polymers, designed for depolymerization, concisely reviewed terms their underlying chemistry potential integration current plastic systems.

Language: Английский

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Nanocatalyzed upcycling of the plastic wastes for a circular economy

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 458, P. 214422 - 214422

Published: Jan. 31, 2022

Language: Английский

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Plastic Waste Recycling, Applications, and Future Prospects for a Sustainable Environment

Sustainability, Journal Year: 2022, Volume and Issue: 14(18), P. 11637 - 11637

Published: Sept. 16, 2022

Plastic waste accumulation has been recognized as one of the most critical challenges modern societies worldwide. Traditional management practices include open burning, landfilling, and incineration, resulting in greenhouse gas emissions economic loss. In contrast, emerging techniques for plastic microwave-assisted conversion, plasma-assisted supercritical water photo reforming to obtain high-value products. Problems with poorly managed are particularly serious developing countries. This review article examines strategies production various high-value-added products from waste. Additionally, uses different sectors, such construction, fuel production, wastewater treatment, electrode materials, carbonaceous nanomaterials, other reviewed. It observed that there is a pressing need utilize circular economy recycling value-added More specifically, limited knowledge on conversion mechanisms efficiency. Therefore, this will help highlight negative environmental impacts importance management.

Language: Английский

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Photoredox-Catalyzed Plastic Waste Conversion: Nonselective Degradation versus Selective Synthesis

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(6), P. 3575 - 3590

Published: Feb. 27, 2023

Plastic waste pollution is becoming one of the most pressing environmental crises due to large-scale production without satisfactory recycling schemes, especially with outbreak COVID-19 pandemic in recent years. Upcycling plastic into valuable chemicals powered by solar energy presents a substantially untapped opportunity turn treasure. In this review, fundamental principles from nonselective degradation selective synthesis are first clarified. Then, we aim outline representative advances photoredox-based catalytic conversion. Particular emphasis placed on valorization regarding versus synthesis. Finally, present challenges and individual insights for further exploration conversion domain. It anticipated that timely critical review would provide an instructive direction foresight plastics value-added chemical feedstocks, thus stimulating development circular sustainable economy coming decades.

Language: Английский

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Recent Advances in Catalytic Chemical Recycling of Polyolefins

ChemCatChem, Journal Year: 2023, Volume and Issue: 15(13)

Published: March 29, 2023

Abstract Polyolefins and especially polyethylenes (LLDPE, LDPE HDPE) polypropylene (PP) contribute a great deal to the growing amounts of plastic waste with combined production share almost 50 % by mass. While being universally applicable, they are mainly used for short‐lived packaging materials that constitute over 60 annual post‐consumer waste. Thus, disproportionately high polyolefins end up as (PCW) management strategies these particularly inert plastics needed. This necessity has promoted research effort dealing valorization discarded but, nevertheless, valuable materials. review aims highlight scientific advances made in chemical polyolefin recycling recent years, focusing, though not exclusively, on catalytic processes recycle various means at more moderate temperatures compared pyrolysis such deconstructing polymer objective upcycling mind or transformation give access functional chemicals.

Language: Английский

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Upcycling chlorinated waste plastics

Nature Reviews Methods Primers, Journal Year: 2023, Volume and Issue: 3(1)

Published: June 8, 2023

Language: Английский

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Recent advances in oxidative degradation of plastics

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

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Catalytic Upcycling of Polyolefins

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(16), P. 9457 - 9579

Published: Aug. 16, 2024

The large production volumes of commodity polyolefins (specifically, polyethylene, polypropylene, polystyrene, and poly(vinyl chloride)), in conjunction with their low unit values multitude short-term uses, have resulted a significant pressing waste management challenge. Only small fraction these is currently mechanically recycled, the rest being incinerated, accumulating landfills, or leaking into natural environment. Since are energy-rich materials, there considerable interest recouping some chemical value while simultaneously motivating more responsible end-of-life management. An emerging strategy catalytic depolymerization, which portion C-C bonds polyolefin backbone broken assistance catalyst and, cases, additional molecule reagents. When products molecules materials higher own right, as feedstocks, process called upcycling. This review summarizes recent progress for four major upcycling strategies: hydrogenolysis, (hydro)cracking, tandem processes involving metathesis, selective oxidation. Key considerations include macromolecular reaction mechanisms relative to mechanisms, design transformations, effect conditions on product selectivity. Metrics describing critically evaluated, an outlook future advances described.

Language: Английский

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Selective Upcycling of Polyethylene Terephthalate towards High‐valued Oxygenated Chemical Methyl p‐Methyl Benzoate using a Cu/ZrO₂ Catalyst

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(11)

Published: Jan. 10, 2024

Abstract Upgrading of polyethylene terephthalate (PET) waste into valuable oxygenated molecules is a fascinating process, yet it remains challenging. Herein, we developed two‐step strategy involving methanolysis PET to dimethyl (DMT), followed by hydrogenation DMT produce the high‐valued chemical methyl p‐methyl benzoate (MMB) using fixed‐bed reactor and Cu/ZrO 2 catalyst. Interestingly, discovered phase structure ZrO significantly regulates selectivity products. Cu supported on monoclinic (5 %Cu/m‐ZrO ) exhibits an exceptional 86 % for conversion MMB, while tetragonal %Cu/t‐ZrO predominantly produces p‐xylene (PX) with 75 %. The superior MMB over Cu/m‐ZrO can be attributed weaker acid sites present m‐ZrO compared t‐ZrO . This weak acidity leads moderate adsorption capability facilitating its desorption. Furthermore, DFT calculations reveal catalyst shows higher effective energy barrier cleavage second C−O bond Cu/t‐ZrO catalyst; this distinction ensures high MMB. not only presents approach upgrading fine chemicals but also offers controlling primary product in multistep reaction.

Language: Английский

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