Enzymes’ Power for Plastics Degradation

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(9), P. 5612 - 5701

Published: March 14, 2023

Plastics are everywhere in our modern way of living, and their production keeps increasing every year, causing major environmental concerns. Nowadays, the end-of-life management involves accumulation landfills, incineration, recycling to a lower extent. This ecological threat environment is inspiring alternative bio-based solutions for plastic waste treatment toward circular economy. Over past decade, considerable efforts have been made degrade commodity plastics using biocatalytic approaches. Here, we provide comprehensive review on recent advances enzyme-based biocatalysis design related processes recycle or upcycle plastics, including polyesters, polyamides, polyurethanes, polyolefins. We also discuss scope limitations, challenges, opportunities this field research. An important message from that polymer-assimilating enzymes very likely part solution reaching

Language: Английский

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Catalytic deconstruction of waste polyethylene with ethylene to form propylene

Science, Journal Year: 2022, Volume and Issue: 377(6614), P. 1561 - 1566

Published: Sept. 29, 2022

The conversion of polyolefins to monomers would create a valuable carbon feedstock from the largest fraction waste plastic. However, breakdown main chains in these polymers requires cleavage carbon–carbon bonds that tend resist selective chemical transformations. Here, we report production propylene by partial dehydrogenation polyethylene and tandem isomerizing ethenolysis desaturated chain. Dehydrogenation high-density with either an iridium-pincer complex or platinum/zinc supported on silica as catalysts yielded dehydrogenated material containing up 3.2% internal olefins; combination second-generation Hoveyda-Grubbs metathesis catalyst [PdP( t Bu) 3 (μ-Br)] 2 isomerization selectively degraded this unsaturated polymer yields exceeding 80%. These results show promise for application mild catalysis deconstruct otherwise stable polyolefins.

Language: Английский

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Concerted and Selective Electrooxidation of Polyethylene‐Terephthalate‐Derived Alcohol to Glycolic Acid at an Industry‐Level Current Density over a Pd−Ni(OH)₂ Catalyst

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(11)

Published: Jan. 19, 2023

Electro-reforming of Polyethylene-terephthalate-derived (PET-derived) ethylene glycol (EG) into fine chemicals and H2 is an ideal solution to address severe plastic pollution. Here, we report the electrooxidation EG glycolic acid (GA) with a high Faraday efficiency selectivity (>85 %) even at industry-level current density (600 mA cm-2 1.15 V vs. RHE) over Pd-Ni(OH)2 catalyst. Notably, stable electrolysis 200 h can be achieved, outperforming all available Pd-based catalysts. Combined experimental theoretical results reveal that 1) OH* generation promoted by Ni(OH)2 plays critical role in facilitating EG-to-GA oxidation removing poisonous carbonyl species, thereby achieving activity stability; 2) Pd downshifted d-band center oxophilic Ni synergistically facilitate rapid desorption transfer GA from active sites inactive sites, avoiding over-oxidation thus selectivity.

Language: Английский

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Understanding the Structure–Activity Relationships in Catalytic Conversion of Polyolefin Plastics by Zeolite-Based Catalysts: A Critical Review

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(24), P. 14882 - 14901

Published: Nov. 23, 2022

Polyolefins, the largest used commodity plastics in world, find extensive application many fields. However, most end up landfills or incineration, leading to severe ecological crises, environmental pollution, and serious resource waste problems. As representatives on chemical upcycling of polyolefin fuels bulk/fine chemicals, catalytic cracking hydrocracking based zeolite metal/zeolite composite catalysts are considered effective paths due their large capacity strong adaptability existing petrochemical equipment. After an overview reaction mechanisms pyrolysis cracking, this review aims comprehensively discuss influence catalyst structure (acidity, pore structure, morphology) activity, selectivity, stability particularly emphasizing importance for matching acidity target product formation. Subsequently, structure–activity relationship between metal site zeolite's acid is also discussed. In end, emerging opportunities challenges proposed promote a more efficient way upcycling.

Language: Английский

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Plastic Waste Valorization by Leveraging Multidisciplinary Catalytic Technologies

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

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A focused review on recycling and hydrolysis techniques of polyethylene terephthalate

Polymer Engineering and Science, Journal Year: 2023, Volume and Issue: 63(9), P. 2651 - 2674

Published: June 21, 2023

Abstract Polyethylene terephthalate (PET) is used in textile and packaging industries. The main source of PET production fossil fuels with limited capacity. Also, products are single use that transform into high volumes wastes, causing ecosystem problems. Recycling proposed to confront this challenge. four major recycling techniques mechanical, chemical, pyrolysis, enzymatic. Mechanical, enzymatic have constrained capabilities manage waste. Chemical the potential path expanding waste possibility upcycling addressing dirty streams. Several chemical methods introduced discussed literature. five glycolysis, alcoholysis, aminolysis, ammonolysis, hydrolysis. This review describes depolymerization via these introduces hydrolysis as one can depolymerize an organic‐free solvent environment. Hydrolysis tolerates mixed wastes streams including copolymers. It helps avoid challenges attributed using organic solvents reaction systems. Moreover, produces terephthalic acid, monomer, which has recently gained attention initiative monomer for production. focuses on three forms hydrolysis—alkaline, neutral, by presenting background studies, issued patents, recent trends application

Language: Английский

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State of the art in the photochemical degradation of (micro)plastics: from fundamental principles to catalysts and applications

Journal of Materials Chemistry A, Journal Year: 2023, Volume and Issue: 11(6), P. 2503 - 2527

Published: Jan. 1, 2023

Plastics and microplastics are major environmental pollutants due to wide applications difficult degradations. Herein, we summarize several studies on degradations of (micro)plastics value-added products intermediates via photocatalysis.

Language: Английский

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Toward carbon neutrality: Selective conversion of waste plastics into value-added chemicals

Matter, Journal Year: 2023, Volume and Issue: 6(10), P. 3322 - 3347

Published: Oct. 1, 2023

Language: Английский

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Upcycling plastic waste to carbon materials for electrochemical energy storage and conversion

Chemical Engineering Journal, Journal Year: 2023, Volume and Issue: 461, P. 141962 - 141962

Published: Feb. 20, 2023

Language: Английский

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Microbial Enzyme Biotechnology to Reach Plastic Waste Circularity: Current Status, Problems and Perspectives

International Journal of Molecular Sciences, Journal Year: 2023, Volume and Issue: 24(4), P. 3877 - 3877

Published: Feb. 15, 2023

The accumulation of synthetic plastic waste in the environment has become a global concern. Microbial enzymes (purified or as whole-cell biocatalysts) represent emerging biotechnological tools for circularity; they can depolymerize materials into reusable building blocks, but their contribution must be considered within context present management practices. This review reports on prospective bio-recycling framework Europe. Available biotechnology support polyethylene terephthalate (PET) recycling. However, PET represents only ≈7% unrecycled waste. Polyurethanes, principal fraction, together with other thermosets and more recalcitrant thermoplastics (e.g., polyolefins) are next plausible target enzyme-based depolymerization, even if this process is currently effective ideal polyester-based polymers. To extend to circularity, optimization collection sorting systems should feed chemoenzymatic technologies treatment mixed In addition, new bio-based lower environmental impact comparison approaches developed (available new) materials, that designed required durability being susceptible action enzymes.

Language: Английский

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