Chemical Research in Chinese Universities, Journal Year: 2024, Volume and Issue: unknown
Published: Nov. 28, 2024
Language: Английский
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
Citations
26
Journal of Materials Chemistry C, Journal Year: 2025, Volume and Issue: unknown
Published: Jan. 1, 2025
Based on the understanding of photothermal catalysis, this review summarizes recent progress CeO 2 -based multicomponent catalysts for catalytic CO reduction.
Language: Английский
Citations
2
Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(26)
Published: April 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
Language: Английский
Citations
7
ACS Nano, Journal Year: 2024, Volume and Issue: 18(17), P. 11438 - 11448
Published: April 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.
Language: Английский
Citations
4
Small, Journal Year: 2025, Volume and Issue: unknown
Published: Feb. 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.
Language: Английский
Citations
0
Acta Chimica Sinica, Journal Year: 2025, Volume and Issue: 83(2), P. 152 - 152
Published: Jan. 1, 2025
Language: Английский
Citations
0
Industrial & Engineering Chemistry Research, Journal Year: 2025, Volume and Issue: unknown
Published: March 4, 2025
Language: Английский
Citations
0
Science China Chemistry, Journal Year: 2025, Volume and Issue: unknown
Published: March 19, 2025
Language: Английский
Citations
0
ACS Sustainable Chemistry & Engineering, Journal Year: 2025, Volume and Issue: unknown
Published: March 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.
Language: Английский
Citations
0
Catalysts, Journal Year: 2025, Volume and Issue: 15(4), P. 335 - 335
Published: March 31, 2025
Chemical recycling of plastic waste, especially polyolefins, into valuable liquid fuels is considerable significance to address the serious issues raised by their threat on environmental and human health. Nevertheless, construction efficient economically viable catalytic systems remains a significant hurdle. Herein, we developed an bifunctional catalyst system comprising γ-Al2O3-supported ruthenium nanoparticles (Ru/γ-Al2O3) β-zeolite for conversion polyolefins gasoline-range hydrocarbons. A yield C5–12 paraffins up 73.4% can be obtained with polyethene as reactant at 250 °C in hydrogen. The Ru sites primarily activate initial cleavage C–H bonds polymer towards formation olefin intermediates, which subsequently go through further cracking isomerization over acid β-zeolite. Employing situ infrared spectroscopy probe–molecule model reactions, our investigation reveals that optimized proportion spatial distribution dual are pivotal tandem process. This optimization synergistically regulates kinetics accelerates intermediate transfer, thereby minimizing production side C1–4 hydrocarbons resulting from over-cracking enhancing fuels. research contributes novel insights design chemical upgrading chemicals, advancing field waste sustainable production.
Language: Английский
Citations
0