Artículos de revistas: "Chemical upcycling of polyethylene"

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Xu, Zhen, Nuwayo Eric Munyaneza, Qikun Zhang, Mengqi Sun, Carlos Posada, Paul Venturo, Nicholas A. Rorrer, Joel Miscall, Bobby G. Sumpter y Guoliang Liu. "Chemical upcycling of polyethylene, polypropylene, and mixtures to high-value surfactants". Science 381, n.º 6658 (11 de agosto de 2023): 666–71. http://dx.doi.org/10.1126/science.adh0993.

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Conversion of plastic wastes to fatty acids is an attractive means to supplement the sourcing of these high-value, high-volume chemicals. We report a method for transforming polyethylene (PE) and polypropylene (PP) at ~80% conversion to fatty acids with number-average molar masses of up to ~700 and 670 daltons, respectively. The process is applicable to municipal PE and PP wastes and their mixtures. Temperature-gradient thermolysis is the key to controllably degrading PE and PP into waxes and inhibiting the production of small molecules. The waxes are upcycled to fatty acids by oxidation over manganese stearate and subsequent processing. PP ꞵ-scission produces more olefin wax and yields higher acid-number fatty acids than does PE ꞵ-scission. We further convert the fatty acids to high-value, large–market-volume surfactants. Industrial-scale technoeconomic analysis suggests economic viability without the need for subsidies.

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Yang, Weina. "Chemical upcycling of PET: a mini-review of converting PET into value-added molecules". Applied and Computational Engineering 7, n.º 1 (21 de julio de 2023): 246–50. http://dx.doi.org/10.54254/2755-2721/7/20230462.

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With the increasing consumption of single-use plastics, a large number of petrochemical resources are used as raw materials, and hundreds of thousands of tons of plastic waste are produced every year. Although there are lots of methods that have been developed to solve this issue by recycling plastic waste, none of them can recover the value of the waste in an efficient way that is less economical cost and less harmful to the environment. Polyethylene terephthalate (PET) is one of the most widely produced single-use polymers. It is challenging to recover the value through mechanical recycling due to the degrading of properties during reprocessing. Chemical upcycling/recycling is an alternative to convert the polymer back to the monomer with less environmental effect, which has lower energy demand. Hydrolysis is one of the common methods in chemical upcycling; it can convert PET waste into value-added materials such as H2 fuel. This paper mainly focuses on the method that converts PET to value-added chemicals through hydrolysis in recent years, so as to offer some references for future researches.

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Zeng, Manhao, Yu-Hsuan Lee, Garrett Strong, Anne M. LaPointe, Andrew L. Kocen, Zhiqiang Qu, Geoffrey W. Coates, Susannah L. Scott y Mahdi M. Abu-Omar. "Chemical Upcycling of Polyethylene to Value-Added α,ω-Divinyl-Functionalized Oligomers". ACS Sustainable Chemistry & Engineering 9, n.º 41 (4 de octubre de 2021): 13926–36. http://dx.doi.org/10.1021/acssuschemeng.1c05272.

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Zhang, Fan, Manhao Zeng, Ryan D. Yappert, Jiakai Sun, Yu-Hsuan Lee, Anne M. LaPointe, Baron Peters, Mahdi M. Abu-Omar y Susannah L. Scott. "Polyethylene upcycling to long-chain alkylaromatics by tandem hydrogenolysis/aromatization". Science 370, n.º 6515 (22 de octubre de 2020): 437–41. http://dx.doi.org/10.1126/science.abc5441.

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The current scale of plastics production and the accompanying waste disposal problems represent a largely untapped opportunity for chemical upcycling. Tandem catalytic conversion by platinum supported on γ-alumina converts various polyethylene grades in high yields (up to 80 weight percent) to low-molecular-weight liquid/wax products, in the absence of added solvent or molecular hydrogen, with little production of light gases. The major components are valuable long-chain alkylaromatics and alkylnaphthenes (average ~C30, dispersity Ð = 1.1). Coupling exothermic hydrogenolysis with endothermic aromatization renders the overall transformation thermodynamically accessible despite the moderate reaction temperature of 280°C. This approach demonstrates how waste polyolefins can be a viable feedstock for the generation of molecular hydrocarbon products.

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Aumnate, Chuanchom, Natalie Rudolph y Majid Sarmadi. "Recycling of Polypropylene/Polyethylene Blends: Effect of Chain Structure on the Crystallization Behaviors". Polymers 11, n.º 9 (6 de septiembre de 2019): 1456. http://dx.doi.org/10.3390/polym11091456.

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The combination of high-density polyethylene (HDPE), low-density polyethylene (LDPE) and polypropylene (PP) is frequently found in polymer waste streams. Because of their similar density, they cannot be easily separated from each other in the recycling stream. Blending of PP/ polyethylenes (PEs) in different ratios possibly eliminate the sorting process used in the regular recycling process. PP has fascinating properties such as excellent processability and chemical resistance. However, insufficient flexibility limits its use for specific applications. Blending of PP with relative flexible PEs might improve its flexibility. This is a unique approach for recycling or upcycling, which aims to maintain or improve the properties of recycled materials. The effects of the branched-chain structures of PEs on the crystallization behavior and the related mechanical properties of such blends were investigated. The overall kinetics of crystallization of PP was significantly influenced by the presence of PEs with different branched-chain structures. The presence of LDPE was found to decrease the overall crystallization rate while the addition of HDPE accelerated the crystallization process of the blends. No negative effect on the mechanical performance and the related crystallinity was observed within the studied parameter range.

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Zhang, Xiaoxia, Shaodan Xu, Junhong Tang, Li Fu y Hassan Karimi-Maleh. "Sustainably Recycling and Upcycling of Single-Use Plastic Wastes through Heterogeneous Catalysis". Catalysts 12, n.º 8 (26 de julio de 2022): 818. http://dx.doi.org/10.3390/catal12080818.

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The huge amount of plastic waste has caused a series of environmental and economic problems. Depolymerization of these wastes and their conversion into desired chemicals have been regarded as a promising route for dealing with these issues, which strongly relies on catalysis for C-C and C-O bond cleavage and selective transformation. Here, we reviewed recent developments in catalysis systems for dealing with single-use plastics, such as polyethylene, polypropylene, and polyethylene glycol terephthalate. The recycling processes of depolymerization into original monomers and conversion into other economic-incentive chemicals were systemically discussed. Rational designs of catalysts for efficient conversion were particularly highlighted. Overall, improving the tolerance of catalysts to impurities in practical plastics, reducing the economic cost during the catalytic depolymerization process, and trying to obtain gaseous hydrogen from plastic wastes are suggested as the developing trends in this field.

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Haque, Zenifar G., Jessica Ortega Ramos y Gerardine G. Botte. "(General Student Poster Award Winner - 2nd Place) Electrochemical Routes for Polymer Upcycling". ECS Meeting Abstracts MA2023-01, n.º 55 (28 de agosto de 2023): 2682. http://dx.doi.org/10.1149/ma2023-01552682mtgabs.

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Approximately 380 million tons of plastic are produced annually, and it is projected to rise to nearly 1.1 billion by 2050 [1]. The largest fraction of such waste consists of polyethylene (PE) and polypropylene (PP), which commonly require energy-intensive methods to achieve depolymerization (such as pyrolysis and hydrogenolysis) due to their remarkable thermodynamic stability. Electrochemical methods are a promising alternative for polymer upcycling as they can utilize renewable energy to create an external potential, overcoming the thermodynamic constraints that the C-C bond cleavage endothermicity imposes on low-temperature polymer conversion. They also offer improved chemical process control by manipulating the electrode potential and minimizing the use and storage of hazardous reagents. Electrochemistry provides a broad range of opportunities for establishing green routes to converting plastic into valuable products. Botte's group is investigating electrochemical approaches to convert polyolefins into valuable products like fuels and fatty acids [2]. Our findings indicate that an electrocatalyst in concert with controlled ionic strength and applied potential enable the selective functionalization of polyolefins and their defragmentation towards target molecules regardless of impurities present in the polymer. In this presentation, we will discuss results of the electrochemical functionalization and deconstruction of low-density polyethylene implementing transition metal electrocatalysts. Acknowledgments: The authors would like to acknowledge the financial support of the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Upcycling of Polymers Program, under Award DE-SC0022307 [1] J. E. Rorrer, C. Troyano-Valls, G. T. Beckham, and Y. Román-Leshkov, "Hydrogenolysis of Polypropylene and Mixed Polyolefin Plastic Waste over Ru/C to Produce Liquid Alkanes," ACS Sustainable Chemistry & Engineering, vol. 9, no. 35, pp. 11661-11666, 2021/09/06 2021, doi: 10.1021/acssuschemeng.1c03786. [2] G. G. Botte, "Process for the Electrochemical Up-Cycling of Plastics (US Pending Patent)," U.S. Patent 63040929, 2020.

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Alali, Sabah A. S., Meshal K. M. B. J. Aldaihani y Khaled M. Alanezi. "Plant Design for the Conversion of Plastic Waste into Valuable Chemicals (Alkyl Aromatics)". Applied Sciences 13, n.º 16 (14 de agosto de 2023): 9221. http://dx.doi.org/10.3390/app13169221.

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The exponential increase in production and consumption of plastic has led to accumulation of plastic waste in the environment, resulting in detrimental impacts on human health and the natural environment. Plastic pollution not only stems from discarded plastics but also from the chemicals released during plastic production and decomposition. Various waste management strategies exist for plastic waste, including landfilling, recycling, conversion to liquid fuel, and upcycling. Landfilling, which is a prevalent method, contributes to long-term environmental degradation. Recycling is practiced worldwide, but its percentage remains low, particularly in regions like South Asia. Conversion to liquid fuel through pyrolysis has been explored as a viable solution, although commercialization faces challenges. Upcycling, which involves depolymerization and repolymerization, offers an avenue to recycle plastic waste into valuable chemicals, specifically focusing on high-density polyethylene (HDPE) and low-density polyethylene (LDPE). Currently, HDPE and LDPE make up 36% of all plastic trash by mass, but they have the potential to account for far more. When plastic waste is incinerated or buried in the earth, it generates carbon dioxide and heat, which pollute our environment. Depolymerization is a way to chemically recycle plastic waste into monomers, but this process requires a large amount of energy. Controlled partial depolymerization can transform PE into new, high-quality products at a temperature of more than 400 °C with or without a catalyst. In this study, we provide a novel approach for the conversion of plastic waste, particularly HDPE and LDPE, into valuable alkyl aromatics. By implementing controlled partial depolymerization, we propose a plant design capable of transforming plastic waste into high-quality chemicals. The design aims to optimize energy consumption, process efficiency, and product quality. The research findings contribute to sustainable plastic waste management and the reduction in environmental pollution caused by plastic waste.

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Otaibi, Ahmed A. Al, Abdulmohsen Khalaf Dhahi Alsukaibi, Md Ataur Rahman, Md Mushtaque y Ashanul Haque. "From Waste to Schiff Base: Upcycling of Aminolysed Poly(ethylene terephthalate) Product". Polymers 14, n.º 9 (2 de mayo de 2022): 1861. http://dx.doi.org/10.3390/polym14091861.

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Recycling plastic waste into valuable materials is one of the contemporary challenges. Every year around 50 million tons of polyethylene terephthalate (PET) bottles are used worldwide. The fact that only a part of this amount is being recycled is putting a burden on the environment. Therefore, a technology that can convert PET-based waste materials into useful ones is highly needed. In the present work, attempts have been made to convert PET-based waste materials into a precursor for others. We report an aminolysed product (3) obtained by aminolysis reaction of PET (1) with 1,2 diaminopropane (DAP, 2) under solvent and catalytic free conditions. The highest amount of monomeric product was obtained upon heating the mixture of diamine and PET at 130 °C. The resulting aminolysed product was then converted to a Schiff-base (5) in 25% yield. The chemical structure of the synthesized compounds was confirmed using multi-spectroscopic techniques. The results of this study will be a valuable addition to the growing body of work on plastic recycling.

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Soong, Ya-Hue Valerie, Margaret J. Sobkowicz y Dongming Xie. "Recent Advances in Biological Recycling of Polyethylene Terephthalate (PET) Plastic Wastes". Bioengineering 9, n.º 3 (27 de febrero de 2022): 98. http://dx.doi.org/10.3390/bioengineering9030098.

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Polyethylene terephthalate (PET) is one of the most commonly used polyester plastics worldwide but is extremely difficult to be hydrolyzed in a natural environment. PET plastic is an inexpensive, lightweight, and durable material, which can readily be molded into an assortment of products that are used in a broad range of applications. Most PET is used for single-use packaging materials, such as disposable consumer items and packaging. Although PET plastics are a valuable resource in many aspects, the proliferation of plastic products in the last several decades have resulted in a negative environmental footprint. The long-term risk of released PET waste in the environment poses a serious threat to ecosystems, food safety, and even human health in modern society. Recycling is one of the most important actions currently available to reduce these impacts. Current clean-up strategies have attempted to alleviate the adverse impacts of PET pollution but are unable to compete with the increasing quantities of PET waste exposed to the environment. In this review paper, current PET recycling methods to improve life cycle and waste management are discussed, which can be further implemented to reduce plastics pollution and its impacts on health and environment. Compared with conventional mechanical and chemical recycling processes, the biotechnological recycling of PET involves enzymatic degradation of the waste PET and the followed bioconversion of degraded PET monomers into value-added chemicals. This approach creates a circular PET economy by recycling waste PET or upcycling it into more valuable products with minimal environmental footprint.

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Szabó, Veronika Anna y Gábor Dogossy. "Investigation of Flame Retardant rPET Foam". Periodica Polytechnica Mechanical Engineering 64, n.º 1 (11 de octubre de 2019): 81–87. http://dx.doi.org/10.3311/ppme.14556.

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The use of plastics in the food and the packaging industries continuously is increasing. In these areas of use the product’s life cycle is short, therefore it quickly turns into waste. The polyethylene terephthalate (PET) - the material that is used as beverage containers - are the material with the greatest environmental load. The physical recycling of PET bottles in large quantities was the research goal. During the work with the help of chemical foaming a closed cell structural foam from PET bottle was produced. The research was carried out with upcycling using chain extender and impact modifier additives. For industrial use a bromine-based flame retardant was used and excellent flame retardancy was achieved. Based on the results obtained, the material previously managed as waste, with the appropriate treatment can be involved into the manufacturing of new products.

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Cho, Hyungjin, Ahyeon Jin, Sun Ju Kim, Youngmin Kwon, Eunseo Lee, Jaeman J. Shin y Byung Hyo Kim. "Conversion of Polyethylene to Low-Molecular-Weight Oil Products at Moderate Temperatures Using Nickel/Zeolite Nanocatalysts". Materials 17, n.º 8 (18 de abril de 2024): 1863. http://dx.doi.org/10.3390/ma17081863.

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Polyethylene (PE) is the most widely used plastic, known for its high mechanical strength and affordability, rendering it responsible for ~70% of packaging waste and contributing to microplastic pollution. The cleavage of the carbon chain can induce the conversion of PE wastes into low-molecular-weight hydrocarbons, such as petroleum oils, waxes, and natural gases, but the thermal degradation of PE is challenging and requires high temperatures exceeding 400 °C due to its lack of specific chemical groups. Herein, we prepare metal/zeolite nanocatalysts by incorporating small-sized nickel nanoparticles into zeolite to lower the degradation temperature of PE. With the use of nanocatalysts, the degradation temperature can be lowered to 350 °C under hydrogen conditions, compared to the 400 °C required for non-catalytic pyrolysis. The metal components of the catalysts facilitate hydrogen adsorption, while the zeolite components stabilize the intermediate radicals or carbocations formed during the degradation process. The successful pyrolysis of PE at low temperatures yields valuable low-molecular-weight oil products, offering a promising pathway for the upcycling of PE into higher value-added products.

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Bustos Seibert, Maximilian, Gerardo Andres Mazzei Capote, Maximilian Gruber, Wolfram Volk y Tim A. Osswald. "Manufacturing of a PET Filament from Recycled Material for Material Extrusion (MEX)". Recycling 7, n.º 5 (20 de septiembre de 2022): 69. http://dx.doi.org/10.3390/recycling7050069.

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Due to its low cost and easy use, the use of material extrusion (MEX) as an additive manufacturing (AM) technology has increased rapidly in recent years. However, this process mainly involves the processing of new plastics. Combining the MEX process with polyethylene terephthalate (PET), which offers a high potential for mechanical and chemical recyclability, opens up a broad spectrum of reutilization possibilities. Turning used PET bottles into printable filament for MEX is not only a recycling option, but also an attractive upcycling scenario that can lead to the production of complex, functional parts. This work analyzes the process of extruding recycled PET bottle flakes into a filament, taking different extrusion screws and extrusion parameters into account. The filament is subsequently processed with MEX into tensile tests. An accompanying thermal, rheological and mechanical characterization of the recycled resin is performed to offer a comparison to the virgin material and a commercially available glycol modified polyethylene terephthalate (PETG) filament. The results show the importance of adequate drying parameters prior to the extrusion and the sensitivity of the material to moisture, leading to degradation. The recycled material is more prone to degradation and presents lower viscosities. Mechanical tests display a higher tensile strength of the recycled and virgin resin in comparison to the PETG. The extrusion of the used PET into a filament and the subsequent printing with the MEX process offers a viable recycling process for the discarded material.

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Jiang, Changle, Yuxin Wang, Thang Luong, Brandon Robinson, Wei Liu y Jianli Hu. "Low temperature upcycling of polyethylene to gasoline range chemicals: Hydrogen transfer and heat compensation to endothermic pyrolysis reaction over zeolites". Journal of Environmental Chemical Engineering 10, n.º 3 (junio de 2022): 107492. http://dx.doi.org/10.1016/j.jece.2022.107492.

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Feng, Xue, Lijun Yang y Lei Zhang. "Sustainable solar-and electro-driven production of high concentration H2O2 coupled to electrocatalytic upcycling of polyethylene terephthalate plastic waste". Chemical Engineering Journal 482 (febrero de 2024): 149191. http://dx.doi.org/10.1016/j.cej.2024.149191.

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Lee, Nahyeon, Junghee Joo, Kun-Yi Andrew Lin y Jechan Lee. "Waste-to-Fuels: Pyrolysis of Low-Density Polyethylene Waste in the Presence of H-ZSM-11". Polymers 13, n.º 8 (7 de abril de 2021): 1198. http://dx.doi.org/10.3390/polym13081198.

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Herein, the pyrolysis of low-density polyethylene (LDPE) scrap in the presence of a H-ZSM-11 zeolite was conducted as an effort to valorize plastic waste to fuel-range chemicals. The LDPE-derived pyrolytic gas was composed of low-molecular-weight aliphatic hydrocarbons (e.g., methane, ethane, propane, ethylene, and propylene) and hydrogen. An increase in pyrolysis temperature led to increasing the gaseous hydrocarbon yields for the pyrolysis of LDPE. Using the H-ZSM-11 catalyst in the pyrolysis of LDPE greatly enhanced the content of propylene in the pyrolytic gas because of promoted dehydrogenation of propane formed during the pyrolysis. Apart from the light aliphatic hydrocarbons, jet fuel-, diesel-, and motor oil-range hydrocarbons were found in the pyrolytic liquid for the non-catalytic and catalytic pyrolysis. The change in pyrolysis temperature for the catalytic pyrolysis affected the hydrocarbon compositions of the pyrolytic liquid more materially than for the non-catalytic pyrolysis. This study experimentally showed that H-ZSM-11 can be effective at producing fuel-range hydrocarbons from LDPE waste through pyrolysis. The results would contribute to the development of waste valorization process via plastic upcycling.

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Leigh Krietsch Boerner. "Upcycling polyethylene". C&EN Global Enterprise 98, n.º 41 (26 de octubre de 2020): 7. http://dx.doi.org/10.1021/cen-09841-scicon7.

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Tiso, Till, Tanja Narancic, Ren Wei, Eric Pollet, Niall Beagan, Katja Schröder, Annett Honak et al. "Towards bio-upcycling of polyethylene terephthalate". Metabolic Engineering 66 (julio de 2021): 167–78. http://dx.doi.org/10.1016/j.ymben.2021.03.011.

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Stadler, Bernhard M. y Johannes G. de Vries. "Chemical upcycling ofpolymers". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 379, n.º 2209 (13 de septiembre de 2021): 20200341. http://dx.doi.org/10.1098/rsta.2020.0341.

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As the production volume of polymers increases, so does the amount of plastic waste. Plastic recycling is one of the concepts to address in this issue. Unfortunately, only a small fraction of plastic waste is recycled. Even with the development of polymers for closed loop recycling that can be in theory reprocessed infinitely the inherent dilemma is that because of collection, cleaning and separation processes the obtained materials simply are not cost competitive with virgin materials. Chemical upcycling, the conversion of polymers to higher valuable products, either polymeric or monomeric, could mitigate this issue. In the following article, we highlight recent examples in this young but fast-growing field. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)'.

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Kamleitner, F., B. Duscher, T. Koch, S. Knaus y V. M. Archodoulaki. "Upcycling of polypropylene-the influence of polyethylene impurities". Polymer Engineering & Science 57, n.º 12 (4 de febrero de 2017): 1374–81. http://dx.doi.org/10.1002/pen.24522.

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Celik, Gokhan, Robert M. Kennedy, Ryan A. Hackler, Magali Ferrandon, Akalanka Tennakoon, Smita Patnaik, Anne M. LaPointe et al. "Upcycling Single-Use Polyethylene into High-Quality Liquid Products". ACS Central Science 5, n.º 11 (23 de octubre de 2019): 1795–803. http://dx.doi.org/10.1021/acscentsci.9b00722.

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Guironnet, Damien y Baron Peters. "Tandem Catalysts for Polyethylene Upcycling: A Simple Kinetic Model". Journal of Physical Chemistry A 124, n.º 19 (20 de abril de 2020): 3935–42. http://dx.doi.org/10.1021/acs.jpca.0c01363.

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KASHIWAGI, Hirotaka, Hiroki KAKIUCHI y Eiji SHIRAI. "UPCYCLING OF WASTE POLYETHYLENE TEREPHTHALATE (PET) INTO ASPHALT MODIFIER". Journal of Japan Society of Civil Engineers, Ser. E1 (Pavement Engineering) 78, n.º 2 (2023): I_31—I_40. http://dx.doi.org/10.2208/jscejpe.78.2_i_31.

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Yuan, Xiangzhou, Nallapaneni Manoj Kumar, Boris Brigljević, Shuangjun Li, Shuai Deng, Manhee Byun, Boreum Lee et al. "Sustainability-inspired upcycling of waste polyethylene terephthalate plastic into porous carbon for CO₂ capture". Green Chemistry 24, n.º 4 (2022): 1494–504. http://dx.doi.org/10.1039/d1gc03600a.

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Industrial-scale upcycling of waste polyethylene terephthalate (PET) plastic into porous carbon globally for CO2 capture was verified as a multifunctional alternative to conventional CO2 absorption and plastic waste management technologies.

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Liu, Pan, Yi Zheng, Yingbo Yuan, Tong Zhang, Qingbin Li, Quanfeng Liang, Tianyuan Su y Qingsheng Qi. "Valorization of Polyethylene Terephthalate to Muconic Acid by Engineering Pseudomonas Putida". International Journal of Molecular Sciences 23, n.º 19 (20 de septiembre de 2022): 10997. http://dx.doi.org/10.3390/ijms231910997.

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Plastic waste is rapidly accumulating in the environment and becoming a huge global challenge. Many studies have highlighted the role of microbial metabolic engineering for the valorization of polyethylene terephthalate (PET) waste. In this study, we proposed a new conceptual scheme for upcycling of PET. We constructed a multifunctional Pseudomonas putida KT2440 to simultaneously secrete PET hydrolase LCC, a leaf-branch compost cutinase, and synthesize muconic acid (MA) using the PET hydrolysate. The final product MA and extracellular LCC can be separated from the supernatant of the culture by ultrafiltration, and the latter was used for the next round of PET hydrolysis. A total of 0.50 g MA was produced from 1 g PET in each cycle of the whole biological processes, reaching 68% of the theoretical conversion. This new conceptual scheme for the valorization of PET waste should have advantages over existing PET upcycling schemes and provides new ideas for the utilization of other macromolecular resources that are difficult to decompose, such as lignin.

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Tennakoon, Akalanka, Xun Wu, Alexander L. Paterson, Smita Patnaik, Yuchen Pei, Anne M. LaPointe, Salai C. Ammal et al. "Catalytic upcycling of high-density polyethylene via a processive mechanism". Nature Catalysis 3, n.º 11 (12 de octubre de 2020): 893–901. http://dx.doi.org/10.1038/s41929-020-00519-4.

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Qiu, Jianfan, Songqi Ma, Sheng Wang, Zhaobin Tang, Qiong Li, Anping Tian, Xiwei Xu, Binbo Wang, Na Lu y Jin Zhu. "Upcycling of Polyethylene Terephthalate to Continuously Reprocessable Vitrimers through Reactive Extrusion". Macromolecules 54, n.º 2 (11 de enero de 2021): 703–12. http://dx.doi.org/10.1021/acs.macromol.0c02359.

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Wang, Tianlin, Chuanchao Shen, Guangren Yu y Xiaochun Chen. "The upcycling of polyethylene terephthalate using protic ionic liquids as catalyst". Polymer Degradation and Stability 203 (septiembre de 2022): 110050. http://dx.doi.org/10.1016/j.polymdegradstab.2022.110050.

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Lee, Yu-Hsuan, Jiakai Sun, Susannah L. Scott y Mahdi M. Abu-Omar. "Quantitative analyses of products and rates in polyethylene depolymerization and upcycling". STAR Protocols 4, n.º 4 (diciembre de 2023): 102575. http://dx.doi.org/10.1016/j.xpro.2023.102575.

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Amalia, Lita, Chia-Yu Chang, Steven S.-S. Wang, Yi-Chun Yeh y Shen-Long Tsai. "Recent advances in the biological depolymerization and upcycling of polyethylene terephthalate". Current Opinion in Biotechnology 85 (febrero de 2024): 103053. http://dx.doi.org/10.1016/j.copbio.2023.103053.

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Nulwala, Hunaid, Carlos Diaz, Ken Medlin y Zhijie Yan. "Compatibilization of Recycled Polypropylene with Polyethylene Blends Via Ionic Liquid to Enhance Mechanical Properties". ECS Meeting Abstracts MA2022-02, n.º 55 (9 de octubre de 2022): 2094. http://dx.doi.org/10.1149/ma2022-02552094mtgabs.

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Polypropylene (PP) is the world's second-largest plastic resin based on production volume, after polyethylene (PE). In 2021, the global production volume of PP amounted to 80 million tons. Less than 2% of total produced PP is recycled annually. PP is sensitive to mixed polymers, and a minor amount of other polymeric contaminants reduces physical properties (Figure 1). To increase the recyclability of PP, there is a specific need to have additives that upcycle. PP represents the most significant opportunity in increasing recycling rates. Ionic liquids (ILs) are universal solvents and can promote compatibilization among different polymers. RoCo has developed several ILs that are non-toxic, and when mixed with polyolefins, they enhance the dispersion of fillers and improve mechanical properties thus opening doors to upcycling of recycled polymers. We have been evaluating the recycling of PP by using ionic liquids. We will be sharing our data on ILs compatibilizer results in retaining and enhancing the mechanical properties of PP even when mixed with 15% PE. Both the tensile and impact properties were improved resulting in upcycling of PP. We are in the process of investigating additional properties such as conductivity and surface properties.

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Villagómez-Salas, Saúl, Palanisamy Manikandan, Salvador Francisco Acuña Guzmán y Vilas G. Pol. "Amorphous Carbon Chips Li-Ion Battery Anodes Produced through Polyethylene Waste Upcycling". ACS Omega 3, n.º 12 (17 de diciembre de 2018): 17520–27. http://dx.doi.org/10.1021/acsomega.8b02290.

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Lou, Xiangxi, Xuan Gao, Yu Liu, Mingyu Chu, Congyang Zhang, Yinghua Qiu, Wenxiu Yang et al. "Highly efficient photothermal catalytic upcycling of polyethylene terephthalate via boosted localized heating". Chinese Journal of Catalysis 49 (junio de 2023): 113–22. http://dx.doi.org/10.1016/s1872-2067(23)64435-3.

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Kim, Jeung Gon. "Chemical recycling of poly(bisphenol A carbonate)". Polymer Chemistry 11, n.º 30 (2020): 4830–49. http://dx.doi.org/10.1039/c9py01927h.

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35

Korley, LaShanda T. J., Thomas H. Epps, Brett A. Helms y Anthony J. Ryan. "Toward polymer upcycling—adding value and tackling circularity". Science 373, n.º 6550 (1 de julio de 2021): 66–69. http://dx.doi.org/10.1126/science.abg4503.

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Plastics have revolutionized modern life, but have created a global waste crisis driven by our reliance and demand for low-cost, disposable materials. New approaches are vital to address challenges related to plastics waste heterogeneity, along with the property reductions induced by mechanical recycling. Chemical recycling and upcycling of polymers may enable circularity through separation strategies, chemistries that promote closed-loop recycling inherent to macromolecular design, and transformative processes that shift the life-cycle landscape. Polymer upcycling schemes may enable lower-energy pathways and minimal environmental impacts compared with traditional mechanical and chemical recycling. The emergence of industrial adoption of recycling and upcycling approaches is encouraging, solidifying the critical role for these strategies in addressing the fate of plastics and driving advances in next-generation materials design.

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36

Wang, Kaili, Fan Yuan y Lei Huang. "Recent Progresses and Challenges in Upcycling of Plastics through Selective Catalytic Oxidation". ChemPlusChem, 26 de febrero de 2024. http://dx.doi.org/10.1002/cplu.202300701.

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Chemical upcycling of plastics provides an important direction for solving the challenging issues of plastic pollution and mitigating the wastage of carbon resources. Among them, catalytic oxidative cracking of plastics to produce high‐value chemicals, such as catalytic oxidation of polyethylene (PE) to produce fatty dicarboxylic acids, catalytic oxidation of polystyrene (PS) to produce benzoic acid, and catalytic oxidation of polyethylene terephthalate (PET) to produce terephthalic acid under mild conditions has attracted increasing attention, and some exciting progress has been made recently. In this article, we will review recent progresses on the catalytic oxidation upcycling of plastics and provide our understanding on the current challenges in catalytic oxidation upcycling of plastics.

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Kogolev, Dmitry, Oleg Semyonov, Nadezhda Metalnikova, Maxim Fatkullin, Raul D. Rodriguez, Petr Slepička, Yusuke Yamauchi, Olga Guselnikova, Rabah Boukherroub y Pavel S. Postnikov. "Waste PET Upcycling to Conductive Carbon-Based Composite through Laser-Assisted Carbonization of UiO-66". Journal of Materials Chemistry A, 2023. http://dx.doi.org/10.1039/d2ta08127j.

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The upcycling of waste polymers into novel materials with high added value is a vital task for modern chemical engineering. Here, we propose diversifying waste polyethylene terephthalate (PET) upcycling to...

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38

Kang, Qingyun, Mingyu Chu, Panpan Xu, Xuchun Wang, Shiqi Wang, Muhan Cao, Oleksandr Ivasenko et al. "Entropy Confinement Promotes Hydrogenolysis Activity for Polyethylene Upcycling". Angewandte Chemie International Edition, 6 de octubre de 2023. http://dx.doi.org/10.1002/anie.202313174.

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Chemical upcycling that catalyzes waste plastics back to high‐purity chemicals holds great promise in end‐of‐life plastics valorization. One of the main challenges in this process is the thermodynamic limitations imposed by the high intrinsic entropy of polymer chains, which makes their adsorption on catalysts unfavorable and the transition state unstable. Here, we overcome this challenge by inducing the catalytic reaction inside mesoporous channels, which possess a strong confined ability to polymer chains, allowing for stabilizing transition state. This approach involves the synthesis of p‐Ru/SBA catalysts, in which Ru nanoparticles are uniformly distributed within the channels of an SBA‐15 support, using a precise‐impregnation method. The unique design of the p‐Ru/SBA catalyst has demonstrated significant improvements in catalytic performance for the conversion of polyethylene into high‐valued liquid fuels, particularly diesel. The catalyst achieved a high solid conversion rate of 1106 g·gRu‐1·h‐1 at 230 °C. Comparatively, this catalytic activity is 4.9 times higher than that of a control catalyst, Ru/SiO2, and 14.0 times higher than that of a commercial catalyst, Ru/C, at 240 °C. This remarkable catalytic activity opens up immense opportunities for the chemical upcycling of waste plastics.

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39

Kang, Qingyun, Mingyu Chu, Panpan Xu, Xuchun Wang, Shiqi Wang, Muhan Cao, Oleksandr Ivasenko et al. "Entropy Confinement Promotes Hydrogenolysis Activity for Polyethylene Upcycling". Angewandte Chemie, 6 de octubre de 2023. http://dx.doi.org/10.1002/ange.202313174.

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Chemical upcycling that catalyzes waste plastics back to high‐purity chemicals holds great promise in end‐of‐life plastics valorization. One of the main challenges in this process is the thermodynamic limitations imposed by the high intrinsic entropy of polymer chains, which makes their adsorption on catalysts unfavorable and the transition state unstable. Here, we overcome this challenge by inducing the catalytic reaction inside mesoporous channels, which possess a strong confined ability to polymer chains, allowing for stabilizing transition state. This approach involves the synthesis of p‐Ru/SBA catalysts, in which Ru nanoparticles are uniformly distributed within the channels of an SBA‐15 support, using a precise‐impregnation method. The unique design of the p‐Ru/SBA catalyst has demonstrated significant improvements in catalytic performance for the conversion of polyethylene into high‐valued liquid fuels, particularly diesel. The catalyst achieved a high solid conversion rate of 1106 g·gRu‐1·h‐1 at 230 °C. Comparatively, this catalytic activity is 4.9 times higher than that of a control catalyst, Ru/SiO2, and 14.0 times higher than that of a commercial catalyst, Ru/C, at 240 °C. This remarkable catalytic activity opens up immense opportunities for the chemical upcycling of waste plastics.

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40

Peng, Yuantao, Jie Yang, Chenqiang Deng, Jin Deng, Li Shen y Yao Fu. "Acetolysis of waste polyethylene terephthalate for upcycling and life-cycle assessment study". Nature Communications 14, n.º 1 (5 de junio de 2023). http://dx.doi.org/10.1038/s41467-023-38998-1.

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AbstractTo reduce environmental pollution and reliance on fossil resources, polyethylene terephthalate as the most consumed synthetic polyester needs to be recycled effectively. However, the existing recycling methods cannot process colored or blended polyethylene terephthalate materials for upcycling. Here we report a new efficient method for acetolysis of waste polyethylene terephthalate into terephthalic acid and ethylene glycol diacetate in acetic acid. Since acetic acid can dissolve or decompose other components such as dyes, additives, blends, etc., Terephthalic acid can be crystallized out in a high-purity form. In addition, Ethylene glycol diacetate can be hydrolyzed to ethylene glycol or directly polymerized with terephthalic acid to form polyethylene terephthalate, completing the closed-loop recycling. Life cycle assessment shows that, compared with the existing commercialized chemical recycling methods, acetolysis offers a low-carbon pathway to achieve the full upcycling of waste polyethylene terephthalate.

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41

Chen, Ziqiu, Emmanuel Ejiogu y Baron Peters. "Quantifying synergy for mixed end-scission and random-scission catalysts in polymer upcycling". Reaction Chemistry & Engineering, 2023. http://dx.doi.org/10.1039/d3re00390f.

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Abstract: The environmental consequences of plastic waste are driving research into many chemical and catalytic recycling strategies. The isomerizing ethenolysis strategy for polyethylene upcycling combines three catalysts to affect two...

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42

Duan, Jindi, Hai Wang, Hangjie Li, Lujie Liu, Kai Fan, Xiangju Meng, Zhiguo Zhang, Liang Wang y Fengshou Xiao. "Selective conversion of polyethylene wastes to methylated aromatics through cascade catalysis". EES Catalysis, 2023. http://dx.doi.org/10.1039/d3ey00011g.

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Upcycling polyethylene into aromatics has attracted much attention for converting plastic wastes into valuable chemicals, but the general routes strongly depend on harsh conditions, precious metals, and/or wide product distributions....

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43

Klauer, Ross R., D. Alex Hansen, Derek Wu, Lummy Maria Oliveira Monteiro, Kevin V. Solomon y Mark A. Blenner. "Biological Upcycling of Plastics Waste". Annual Review of Chemical and Biomolecular Engineering, 15 de abril de 2024. http://dx.doi.org/10.1146/annurev-chembioeng-100522-115850.

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Plastic wastes accumulate in the environment, impacting wildlife and human health and representing a significant pool of inexpensive waste carbon that could form feedstock for the sustainable production of commodity chemicals, monomers, and specialty chemicals. Current mechanical recycling technologies are not economically attractive due to the lower-quality plastics that are produced in each iteration. Thus, the development of a plastics economy requires a solution that can deconstruct plastics and generate value from the deconstruction products. Biological systems can provide such value by allowing for the processing of mixed plastics waste streams via enzymatic specificity and using engineered metabolic pathways to produce upcycling targets. We focus on the use of biological systems for waste plastics deconstruction and upcycling. We highlight documented and predicted mechanisms through which plastics are biologically deconstructed and assimilated and provide examples of upcycled products from biological systems. Additionally, we detail current challenges in the field, including the discovery and development of microorganisms and enzymes for deconstructing non–polyethylene terephthalate plastics, the selection of appropriate target molecules to incentivize development of a plastic bioeconomy, and the selection of microbial chassis for the valorization of deconstruction products.

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44

Osei, Dacosta, Lakshmiprasad Gurrala, Aria Sheldon, Jackson Mayuga, Clarissa Lincoln, Nicholas A. Rorrer y Ana Rita C. Morais. "Subcritical CO₂–H₂O hydrolysis of polyethylene terephthalate as a sustainable chemical recycling platform". Green Chemistry, 2024. http://dx.doi.org/10.1039/d3gc04576e.

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45

Obando, Alejandro Guillen, Mark Robertson, Chinwendu Umeojiako, Paul Smith, Anthony Griffin, Yizhi Xiang y Zhe Qiang. "Catalyst-free upcycling of crosslinked polyethylene foams for CO2 capture". Journal of Materials Research, 1 de mayo de 2023. http://dx.doi.org/10.1557/s43578-023-01016-7.

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AbstractRecycling of crosslinked plastics is an intractable challenge due to their very limited amenability to mechanical reprocessing. While a variety of chemical recycling methods have been recently reported, these systems primarily focus on deconstructing or depolymerizing plastics to monomers and liquid fuels, which their subsequent use likely involves additional energy consumption and greenhouse gas emission. In this work, we present a simple, scalable, and catalyst-free method for directly converting crosslinked polyethylene (PE) foams into porous carbon materials. This process is enabled by sulfonation-based crosslinking, allowing the conversion of PE to become efficient carbon precursors, while retaining the high porosity feature from the foam precursors. Through two steps of sulfonation and carbonization, derived carbons contain a relatively high surface area and sulfur-doped framework. As a result, these materials can exhibit high CO2 sorption capacity and CO2/N2 selectivity. This work presents a viable pathway to address two grand-scale environmental challenges of plastic wastes and greenhouse gas emissions. Graphical abstract

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46

Zhou, Hua, Yue Ren, Zhenhua Li, Ming Xu, Ye Wang, Ruixiang Ge, Xianggui Kong, Lirong Zheng y Haohong Duan. "Electrocatalytic upcycling of polyethylene terephthalate to commodity chemicals and H2 fuel". Nature Communications 12, n.º 1 (17 de agosto de 2021). http://dx.doi.org/10.1038/s41467-021-25048-x.

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AbstractPlastic wastes represent a largely untapped resource for manufacturing chemicals and fuels, particularly considering their environmental and biological threats. Here we report electrocatalytic upcycling of polyethylene terephthalate (PET) plastic to valuable commodity chemicals (potassium diformate and terephthalic acid) and H2 fuel. Preliminary techno-economic analysis suggests the profitability of this process when the ethylene glycol (EG) component of PET is selectively electrooxidized to formate (>80% selectivity) at high current density (>100 mA cm−2). A nickel-modified cobalt phosphide (CoNi0.25P) electrocatalyst is developed to achieve a current density of 500 mA cm−2 at 1.8 V in a membrane-electrode assembly reactor with >80% of Faradaic efficiency and selectivity to formate. Detailed characterizations reveal the in-situ evolution of CoNi0.25P catalyst into a low-crystalline metal oxy(hydroxide) as an active state during EG oxidation, which might be responsible for its advantageous performances. This work demonstrates a sustainable way to implement waste PET upcycling to value-added products.

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47

Li, Rongxiang, Wei Zeng, Runyao Zhao, Yanfei Zhao, Yuepeng Wang, Fengtao Zhang, Minhao Tang et al. "TiO2 nanoparticle supported Ru catalyst for chemical upcycling of polyethylene terephthalate to alkanes". Nano Research, 10 de junio de 2023. http://dx.doi.org/10.1007/s12274-023-5772-1.

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48

Chen, Zhijie, Renji Zheng, Teng Bao, Tianyi Ma, Wei Wei, Yansong Shen y Bing-Jie Ni. "Dual-Doped Nickel Sulfide for Electro-Upgrading Polyethylene Terephthalate into Valuable Chemicals and Hydrogen Fuel". Nano-Micro Letters 15, n.º 1 (11 de septiembre de 2023). http://dx.doi.org/10.1007/s40820-023-01181-8.

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Abstract Electro-upcycling of plastic waste into value-added chemicals/fuels is an attractive and sustainable way for plastic waste management. Recently, electrocatalytically converting polyethylene terephthalate (PET) into formate and hydrogen has aroused great interest, while developing low-cost catalysts with high efficiency and selectivity for the central ethylene glycol (PET monomer) oxidation reaction (EGOR) remains a challenge. Herein, a high-performance nickel sulfide catalyst for plastic waste electro-upcycling is designed by a cobalt and chloride co-doping strategy. Benefiting from the interconnected ultrathin nanosheet architecture, dual dopants induced up-shifting d band centre and facilitated in situ structural reconstruction, the Co and Cl co-doped Ni3S2 (Co, Cl-NiS) outperforms the single-doped and undoped analogues for EGOR. The self-evolved sulfide@oxyhydroxide heterostructure catalyzes EG-to-formate conversion with high Faradic efficiency (> 92%) and selectivity (> 91%) at high current densities (> 400 mA cm−2). Besides producing formate, the bifunctional Co, Cl-NiS-assisted PET hydrolysate electrolyzer can achieve a high hydrogen production rate of 50.26 mmol h−1 in 2 M KOH, at 1.7 V. This study not only demonstrates a dual-doping strategy to engineer cost-effective bifunctional catalysts for electrochemical conversion processes, but also provides a green and sustainable way for plastic waste upcycling and simultaneous energy-saving hydrogen production.

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49

Sun, Jiakai, Yu-Hsuan Lee, Ryan D. Yappert, Anne M. LaPointe, Geoffrey W. Coates, Baron Peters, Mahdi M. Abu-Omar y Susannah L. Scott. "Bifunctional tandem catalytic upcycling of polyethylene to surfactant-range alkylaromatics". Chem, junio de 2023. http://dx.doi.org/10.1016/j.chempr.2023.05.017.

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50

Dissanayake, Lakshika y Lahiru N. Jayakody. "Engineering Microbes to Bio-Upcycle Polyethylene Terephthalate". Frontiers in Bioengineering and Biotechnology 9 (28 de mayo de 2021). http://dx.doi.org/10.3389/fbioe.2021.656465.

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Polyethylene terephthalate (PET) is globally the largest produced aromatic polyester with an annual production exceeding 50 million metric tons. PET can be mechanically and chemically recycled; however, the extra costs in chemical recycling are not justified when converting PET back to the original polymer, which leads to less than 30% of PET produced annually to be recycled. Hence, waste PET massively contributes to plastic pollution and damaging the terrestrial and aquatic ecosystems. The global energy and environmental concerns with PET highlight a clear need for technologies in PET “upcycling,” the creation of higher-value products from reclaimed PET. Several microbes that degrade PET and corresponding PET hydrolase enzymes have been successfully identified. The characterization and engineering of these enzymes to selectively depolymerize PET into original monomers such as terephthalic acid and ethylene glycol have been successful. Synthetic microbiology and metabolic engineering approaches enable the development of efficient microbial cell factories to convert PET-derived monomers into value-added products. In this mini-review, we present the recent progress of engineering microbes to produce higher-value chemical building blocks from waste PET using a wholly biological and a hybrid chemocatalytic–biological strategy. We also highlight the potent metabolic pathways to bio-upcycle PET into high-value biotransformed molecules. The new synthetic microbes will help establish the circular materials economy, alleviate the adverse energy and environmental impacts of PET, and provide market incentives for PET reclamation.

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