Hierarchical FAU Zeolites Boosting the Hydrocracking of Polyolefin Waste into Liquid Fuels

ACS Sustainable Chemistry & Engineering, Journal Year: 2024, Volume and Issue: 12(15), P. 6013 - 6022

Published: April 3, 2024

Conventional metal-zeolite catalysts struggle with hydrocracking polyolefin wastes due to a significant mismatch between the size of large polymer molecules and micropores zeolites. This severely constrains diffusion site accessibility, resulting in low efficiency. Here, we unveil simple hydrothermal treatment commercial Y zeolite that creates hierarchical (Y–H), which possesses substantial layers mesoporous nanoflakes on its surface, constructing unique pore architecture. network integrates (ca. 13 nm) medium 4 mesopores original (<1 critically without altering zeolite's topology, crystallinity, or acidity. Compared Pt/Al2O3, Y–H Pt/Al2O3 exhibit remarkable 4-fold increase activity, is attributed enhanced accessibility acid sites, providing sufficient cascade cracking space for macromolecular polyolefins be efficiently converted into small, branched alkanes. Notably, catalyst achieves an impressive 96.8% PE conversion 90.8% selectivity toward value-added gasoline diesel fuels (C5–20) within h at 280 °C. work not only demonstrates pivotal role networks but also highlights their broader applicability plastic waste upcycling.

Language: Английский

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Chemical Upcycling of Polyolefin Plastics Using Structurally Well-defined Catalysts

JACS Au, Journal Year: 2024, Volume and Issue: 4(6), P. 2081 - 2098

Published: June 4, 2024

Single-use polyolefins are widely used in our daily life and industrial production due to their light weight, low cost, superior stability, durability. However, the rapid accumulation of plastic waste low-profit recycling methods resulted a global crisis. Catalytic hydrogenolysis is regarded as promising technique, which can effectively selectively convert polyolefin value-added products. In this perspective, we focus on design synthesis structurally well-defined catalysts across mesoscopic, nanoscopic, atomic scales, accompanied by insights into future directions catalyst for further enhancing catalytic performance. These principles also be applied depolymerization other polymers ultimately realize chemical upcycling plastics.

Language: Английский

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Assessment of transport phenomena in catalyst effectiveness for chemical polyolefin recycling

Nature Chemical Engineering, Journal Year: 2024, Volume and Issue: 1(9), P. 565 - 575

Published: Aug. 28, 2024

Abstract Since the dawn of agitated brewing in Paleolithic era, effective mixing has enabled efficient reactions. Emerging catalytic chemical polyolefin recycling processes present unique challenges, considering that polymer melt a viscosity three orders magnitude higher than honey. The lack protocols to achieve may have resulted suboptimal catalyst effectiveness. In this study, we tackled hydrogenolysis commercial-grade high-density polyethylene and polypropylene show how different stirring strategies can create differences up 85% 40% effectiveness selectivity, respectively. reaction develops near H 2 –melt interface, with extension interface access particles main performance drivers. Leveraging computational fluid dynamics simulations, identified power number 15,000–40,000 maximize factor optimize parameters. This temperature- pressure-independent model holds across range 1–1,000 Pa s. Temperature gradients quickly become relevant for reactor scale-up.

Language: Английский

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Hydrocarbon Deposition during Polyolefin Upcycling: Irreversible Adsorption and Surface Reactions of Polyethylene and Ethylene Oligomers on Silica Supports

Industrial & Engineering Chemistry Research, Journal Year: 2025, Volume and Issue: unknown

Published: March 12, 2025

Language: Английский

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Reductive Upcycling of Polyolefins, Polyesters and Mixed Plastic Wastes to Valuable Chemicals: Bridging Chemical Catalysis With Plastic Waste Management

Advanced Sustainable Systems, Journal Year: 2025, Volume and Issue: unknown

Published: March 20, 2025

Abstract The unmatched applications of plastic commodities are evident from the enormous production, reaching over 400 million tons per year in recent times. Contrastingly, lack proper management leads to a large accumulation waste, majorly including polyolefins and polyesters. Conventional methods possess significant drawbacks like cost‐ineffectiveness greenhouse gas emissions. Over last decade, chemical processes have shown promising potential for but only hold 0.1% share recycling. catalytic offer excellent protocols obtain high‐value liquid fuels, waxes, chemicals waste. This review presents an elaborate discussion on state art reductive upcycling polyolefins, polyesters, mixed initially discusses alarming statistics plastics conventional approaches followed by introduction processes. Further, various recently reported strategies been elaborated detail catalyst deactivation, technoeconomic analysis, life cycle assessment deeper understanding current this research field. Finally, detailed summary along with existing challenges countermeasures is discussed open new avenues waste research.

Language: Английский

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Polyolefin Recycling with Binary Cobalt–Nickel Nanosheets

Small, Journal Year: 2025, Volume and Issue: unknown

Published: March 31, 2025

Abstract The recycling of polyolefin plastics into value‐added chemicals has emerged as a new frontier regarding the current environmental concerns. In this work, it is demonstrated that binary cobalt‐nickel nanosheets (Co─Ni NSs) can serve non‐noble catalyst for polyethylene and polypropylene plastics. Detailed analysis implies strong synergy between Co Ni in Co─Ni NSs enables electron transfer from to enhances adsorption abilities H 2 C─C chain, realizing cracking plastic liquid products with selectivity 83.3% at conversion >98%. Impressively, such realize successful commercial wastes products. Given enhanced stability, high products, low‐cost NSs, work provides feasible strategy plastics, which will attract extensive attention various fields including catalysis, materials, energy, beyond.

Language: Английский

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Ru-Catalyzed Polyethylene Hydrogenolysis under Quasi-Supercritical Conditions

JACS Au, Journal Year: 2025, Volume and Issue: 5(4), P. 1760 - 1770

Published: April 16, 2025

Ru/C-catalyzed polyethylene (PE) and hydrocarbon hydrogenolysis under quasi-supercritical fluid of isopentane was kinetically mechanistically investigated. PE with C-C C-H cleavage showed zeroth order, suggesting strong adsorption hydrocarbons. yielded broad product distribution heavy (C21-40) diesel-range (C11-20) hydrocarbons in the primary step due to stochastic over Ru surface. Catalytic n-hexadecane, squalane, light such as n-pentane, iso-pentane, n-hexane further described reactivity between secondary carbons, i.e., 1C-2C 2C-2C, which has an order magnitude higher rate than that involving a tertiary carbon. The saturated surface lower carbon therefore, imited sovlent conversion during hydrogenolysis, whereas leading selective conversion. Using hexadecane, we observed comparable rates H2 D2 (k H /k D ∼ 1), indicating relevant facilitating rehydrogenation. However, normal kinetic isotope effect hexadecane deuterated C16H34 C16D34 5) revealed dehydrogenation, cleavage, can be involved kinetic. By considering 8-fold H-D exchange compared for attributed C-D bond dissociation energy being 3 kJ/mol bond. Increasing pressure favors internal terminal one. This minimizes formation hydrocarbons, particularly methane. increase increases coverage adsorbed hydrogen on particles competitive polyethylene, which, turn, reduces rates.

Language: Английский

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Tandem Catalysis for Plastic Depolymerization: In Situ Hydrogen Generation via Methanol APR for Sustainable PE Hydrogenolysis

Angewandte Chemie, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 22, 2025

Abstract Depolymerizing plastic waste through hydrogen‐based processes, such as hydrogenolysis and hydrocracking, presents a promising solution for converting plastics into liquid fuels. However, conventional hydrogen production methods rely heavily on fossil fuels, exacerbating global warming. This study introduces novel approach to that utilizes in situ generated via the aqueous phase reforming (APR) of methanol, biomass‐derived chemical offering more sustainable alternative. Our results show bimetallic Ru−Pt/TiO 2 catalyst achieved high conversion (85.1 %) selectivity (81.0 towards fuels lubricant oils tandem process combining polyethylene (PE) methanol APR. By tuning metal loading, we identified Pt enhances APR, while Ru drives C−C bond cleavage, which is crucial PE hydrogenolysis. Isotope labeling analysis confirmed from APR effectively utilized reaction. method was also successfully applied post‐consumer polyolefin waste, with toward valuable products ranging 75.0 % 88.9 %. highlights an innovative strategy reduce reliance fossil‐fuel‐derived depolymerization, promoting both sustainability environmental protection.

Language: Английский

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Tandem Catalysis for Plastic Depolymerization: In Situ Hydrogen Generation via Methanol APR for Sustainable PE Hydrogenolysis

Angewandte Chemie International Edition, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 22, 2025

Depolymerizing plastic waste through hydrogen-based processes, such as hydrogenolysis and hydrocracking, presents a promising solution for converting plastics into liquid fuels. However, conventional hydrogen production methods rely heavily on fossil fuels, exacerbating global warming. This study introduces novel approach to that utilizes in situ generated via the aqueous phase reforming (APR) of methanol, biomass-derived chemical offering more sustainable alternative. Our results show bimetallic Ru-Pt/TiO2 catalyst achieved high conversion (85.1 %) selectivity (81.0 towards fuels lubricant oils tandem process combining polyethylene (PE) methanol APR. By tuning metal loading, we identified Pt enhances APR, while Ru drives C-C bond cleavage, which is crucial PE hydrogenolysis. Isotope labeling analysis confirmed from APR effectively utilized reaction. method was also successfully applied post-consumer polyolefin waste, with toward valuable products ranging 75.0 % 88.9 %. highlights an innovative strategy reduce reliance fossil-fuel-derived depolymerization, promoting both sustainability environmental protection.

Language: Английский

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Production of Branched Alkanes by Upcycling of Waste Polyethylene over Controlled Acid Sites of SO4/ZrO2‐Al2O3 Catalyst

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 14, 2024

Abstract Branched alkanes, which enhance the octane number of gasoline, can be produced from waste polyethylene. However, achieving highly selective production branched alkanes presents a significant challenge in upcycling Here, we report one‐pot process to convert polyethylene into gasoline‐range hydrocarbons (C 4 –C 13 ) with yield 73.3 % over SO /ZrO 2 ‐Al O 3 catalyst at 280 °C. The proportion reaches 90.1 within C fraction. Incorporation sulfate group endows strong Lewis acid sites and weak moderate Brønsted sites. In situ X‐ray absorption, infrared spectroscopy, small angle neutron scattering, DFT calculations reveal that activation occurs through synergy between groups (Zr sites). preferentially catalyze isomerization type A β‐scission processes, favors formation while suppressing competing reactions produce straight‐chain alkanes.

Language: Английский

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