Catalytic Upcycling of Polyolefins

Chemical Reviews, Год журнала: 2024, Номер 124(16), С. 9457 - 9579

Опубликована: Авг. 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.

Язык: Английский

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Upgrading polyolefin plastics: experiences from petroleum refining and distinct characteristics

Science China Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Март 19, 2025

Язык: Английский

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Enhanced photothermal catalytic CO₂ reduction by CeO₂-based multicomponent catalysts

Journal of Materials Chemistry C, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

Based on the understanding of photothermal catalysis, this review summarizes recent progress CeO 2 -based multicomponent catalysts for catalytic CO reduction.

Язык: Английский

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Micelles Cascade Assembly to Tandem Porous Catalyst for Waste Plastics Upcycling

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(26)

Опубликована: Апрель 22, 2024

Catalytic upcycling of polyolefins into high-value chemicals represents the direction in end-of-life plastics valorization, but poses great challenges. Here, we report synthesis a tandem porous catalyst via micelle cascade assembly strategy for selectively catalytic cracking polyethylene olefins at low temperature. A hierarchically silica layer from mesopore to macropore is constructed on surface microporous ZSM-5 nanosheets through dynamic micelles. The outer arrays can adsorb bulky quickly by capillary and hydrophobic effects, enhancing diffusion access active sites. middle mesopores present nanoconfinement space, pre-cracking intermediates weak acid sites, which then transport zeolites micropores further strong Brønsted acidic structures, mimicking biomimetic protease clefts, ideally match steps polyolefins, thus suppressing coke formation facilitating product escape. As result, light hydrocarbons (C

Язык: Английский

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Hydrogen Bubbles: Harmonizing Local Hydrogen Transfer for Efficient Plastic Hydro-Depolymerization

ACS Nano, Год журнала: 2024, Номер 18(17), С. 11438 - 11448

Опубликована: Апрель 16, 2024

Hydro-depolymerization presents a promising avenue for transforming plastic waste into high-value hydrocarbons, offering significant potential value-added recycling. However, major challenge in this method arises from kinetic limitations due to insufficient hydrogen concentration near the active sites, requiring optimal catalytic performance only at higher pressures. In study, we address hurdle by developing "hydrogen bubble catalysts" featuring Ru nanoparticles within mesoporous SBA-15 channels (Ru/SBA). The distinctive feature of Ru/SBA catalysts lies their capacity physical storage and chemically reversible spillover, ensuring timely ample supply. Under identical reaction conditions, activity surpassed that Ru/SiO2 (no capacity) over 4-fold. This substantial enhancement provides opportunities atmospheric pressure hydro-depolymerization waste.

Язык: Английский

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Unleashing High Yield Urea Production by Pulse Electrodeposition of Bi/Cu via Co-reduction of N₂ and CO₂

ACS Energy Letters, Год журнала: 2024, Номер unknown, С. 85 - 93

Опубликована: Дек. 13, 2024

The expanding agricultural practices rely on carbon- and energy-intensive Bosch–Meiser processes for urea synthesis. Alternatively, electrochemical coupling of CO2 N2 is emerging as a sustainable approach. Unfortunately, the high energy barrier cracking C–N bond limits synthesis efficiency. Herein, we have electrodeposited Bi Cu foil via triple pulse voltage, fabricated Bi(0.01 V)@Cu electrode demonstrates yield rate 646 μg h–1 mg–1cat. with 70.7% Faradaic efficiency at −0.45 V vs RHE. isotopic labeling experiments assert that produced solely from dissolved gases. More importantly, utilized in situ Raman spectroscopy Fourier transform infrared (FTIR) measurements to monitor real-time formation urea, further supported by microelectrochemical approach using Pt-microelectrode results were verified density functional theory (DFT) analysis. Moving step forward, plant growth flowering upon addition extracted been demonstrated practical application.

Язык: Английский

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Oxygen‐Doped γ‐Mo₂N as High‐Performance Catalyst for Ammonia Decomposition

Small, Год журнала: 2025, Номер unknown

Опубликована: Фев. 16, 2025

Abstract γ‐Mo 2 N catalysts exhibit excellent activity and stability in ammonia decomposition reactions. However, the influence of oxygen on its is still unknown. In this work, two with different content are synthesized using temperature‐programmed nitridation α‐MoO 3 . The highly oxidized their performance closely related to content. high (HO‐γ‐Mo N) much higher, whose H formation rate at 550 °C 3.3 times higher than low (LO‐γ‐Mo N). This mainly attributed aspects: one hand, valence state Mo HO‐γ‐Mo leads stronger Mo─NH bonds, which promotes adsorption activation NH On other generated by N─H bond breaking more easily migrated O, avoids excessive occupying active sites alleviates negative effect hydrogen poisoning.

Язык: Английский

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Current Advances of Solid Acid Catalysts

Acta Chimica Sinica, Год журнала: 2025, Номер 83(2), С. 152 - 152

Опубликована: Янв. 1, 2025

Язык: Английский

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Boosting Degradation of Polyethylene at Room Temperature

Industrial & Engineering Chemistry Research, Год журнала: 2025, Номер unknown

Опубликована: Март 4, 2025

Язык: Английский

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Tailored Ru Catalysts on Gamma Alumina: Enhancing Polyethylene Hydrogenolysis for High-Value Liquid Fuel Production

ACS Sustainable Chemistry & Engineering, Год журнала: 2025, Номер unknown

Опубликована: Март 26, 2025

Nowadays, plastics are increasingly used in the activities of our daily lives, including packaging different food and brewing companies, cosmetics, pharmaceuticals, other production sectors. Plastics produced through biochemical process polymerization or polycondensation. The late use generated plastic waste has many adverse effects on environment if it is treated managed improperly. Herein, a novel ruthenium (Ru) supported gamma alumina (Ru/γ-Al2O3) catalyst was developed as an efficient to boost polyethylene (PE) hydrogenolysis produce high-value liquid fuel. Under mild reaction conditions (240 °C, 2.0 MPa, 12 h), catalytic performance Ru/γ-Al2O3 with carrier forms Ru contents studied (catalyst/PE = 1:1). results revealed that 1Ru/γ-Al2O3 nanosheet (NS) catalyst, containing approximately 1 wt % Ru, exhibited remarkable PE hydrogenolysis. It achieved high conversion 97.50% yielded significant amount fuel (C5–C21) at 70.65%, 75.65% selectivity (C5–C21). enhancement primarily attributed abundance surface-exposed medium acidic sites, coupled presence suitably electron-deficient species highly dispersed induced by metal-support interactions. findings provide valuable insights for design catalysts aimed improving yield fuels plastics.

Язык: Английский

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