Construction of Highly Active Pd–Ti³⁺ Sites in Defective Pd/TiO₂ Catalysts for Efficient Hydrogenation of Styrene–Butadiene–Styrene

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(3), P. 1432 - 1442

Published: Jan. 12, 2024

Defect-rich Pd/TiO2 catalysts are intensively adopted in heterogeneous hydrogenation reactions; however, the complexity of defect structure makes it difficult to precisely identify which Pd-defect combination dominates catalytic activity. Herein, defective TiO2 nanoflakes with tunable ratios Vo Ti3+ defects were synthesized and used construct Pd–Vo Pd–Ti3+ active sites after loading Pd investigate role regulating structural properties catalysts. Combining experimental results theoretical calculations, we reveal that both act as electron donors for induce strong metal–support interaction. When compared defect, behaves more significantly donates electrons, causing species on be better dispersed rich electrons. These unique features endow centers enhanced adsorption–activation ability toward C═C H2 well reduced energy barrier rate-limiting step, thus improving intrinsic The site manifests a high turnover frequency 348 h–1 degree 97% styrene–butadiene–styrene, outperforms (254 78%) nanoparticle (217 53%). This work provides deep insight into metal sites, can guide development high-performance versatile applications.

Language: Английский

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From Charge to Spin: An In‐Depth Exploration of Electron Transfer in Energy Electrocatalysis

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(37)

Published: March 14, 2024

Abstract Catalytic materials play crucial roles in various energy‐related processes, ranging from large‐scale chemical production to advancements renewable energy technologies. Despite a century of dedicated research, major enduring challenges associated with enhancing catalyst efficiency and durability, particularly green electrochemical reactions, remain. Focusing only on either the crystal structure or electronic is deemed insufficient break linear scaling relationship (LSR), which golden rule for design advanced catalysts. The discourse this review intricately outlines essence heterogeneous catalysis reactions by highlighting vital played electron properties. physical properties charge spin that govern efficiencies are analyzed. Emphasis placed pronounced influence external fields perturbing LSR, underscoring role plays advancing high‐performance design. culminates proffering insights into potential applications catalysis, concluding discussion extant inherent limitations.

Language: Английский

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Stable Interfacial Ruthenium Species for Highly Efficient Polyolefin Upcycling

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(10), P. 7076 - 7087

Published: March 1, 2024

The present polyolefin hydrogenolysis recycling cases acknowledge that zerovalent Ru exhibits high catalytic activity. A pivotal rationale behind this assertion lies in the propensity of majority species to undergo reduction within milieu. Nonetheless, suitability as an optimal structural configuration for accommodating multiple elementary reactions remains ambiguous. Here, we have constructed stable Ru0–Ruδ+ complex species, even under reaction conditions, through surface ligand engineering commercially available Ru/C catalysts. Our findings unequivocally demonstrate surface-ligated can be stabilized form a Ruδ+ state, which, turn, engenders perturbation σ bond electron distribution carbon chain, ultimately boosting rate-determining step C–C scission. optimized catalysts reach solid conversion rate 609 g·gRu–1·h–1 polyethylene. This achievement represents 4.18-fold enhancement relative pristine catalyst while concurrently preserving remarkable 94% selectivity toward valued liquid alkanes. Of utmost significance, extended gentle mixing solution at room temperature, thus rendering it amenable swift integration into industrial processes involving degradation.

Language: Английский

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Catalytic Upcycling of Polyolefins

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

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Review on Catalytic Depolymerization of Polyolefin Waste by Hydrogenolysis: State-of-the-Art and Outlook

Energy & Fuels, Journal Year: 2024, Volume and Issue: 38(3), P. 1676 - 1691

Published: Jan. 22, 2024

Mechanical recycling of plastic waste is not sustainable and inefficient in terms the resources needed to accomplish process, quality materials obtained from this technique substandard. Chemical polymers appears be preferable because technology allows for production new materials. This review compiles most recent research which selected transition metals are used as catalysts hydrogenolytic depolymerization polyolefins a polymer upcycling process. Hydrogenolysis an emerging chemical method that uses transition-metal complexes presence hydrogen cleave C–C bonds substances into shorter hydrocarbons. Transition such Ruthenium (Ru), Platinum (Pt), Nickel (Ni), Cobalt (Co), Zirconium (Zr), Tantalum (Ta), Rhodium (Rh) have been utilized recently type reaction. hydrogenolysis can produce valuable hydrocarbon products, gas/liquid fuels lubricating oils, under relatively milder operational conditions with less environmental impact. The focused on supported metal organometal catalytic system their mechanism polyolefin pathways detailed investigation impact reaction parameters high gasoline, diesel, light lubricants.

Language: Английский

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Size and Structure Effects of Carbon-Supported Ruthenium Nanoparticles on Waste Polypropylene Hydrogenolysis Activity, Selectivity, and Product Microstructure

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(5), P. 3228 - 3240

Published: Feb. 15, 2024

Hydrogenolysis of plastic waste using Ru-based catalysts is promising for deconstructing polyolefins into lower molecular weight products. Yet, the effect catalyst atomic structure and size on activity product selectivity poorly understood. Herein, we expose metal particle isotactic-polypropylene (i-PP) hydrogenolysis over Ru supported carbon. Despite similar distributions solid liquid products, their physical properties are distinct due to different chain regio-irregular CH3 sequences steric pentads containing racemo configurations. We propose that i-PP entails an interplay C–C bond scission stereoisomerization. The active site's local electronic environment dictate former, whereas polymer–catalyst surface interactions creating suitable polymer conformations control latter. stereoisomerization structure-sensitive. Small, disordered nanoclusters effective in scission, larger nanoparticles promote hypothesize a heterogeneous distribution sites essential deconstruction (lubricant base oil) quality control.

Language: Английский

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Upcycling Waste Plastics with a C–C Backbone by Heterogeneous Catalysis

Langmuir, Journal Year: 2024, Volume and Issue: 40(10), P. 5077 - 5089

Published: Feb. 15, 2024

Plastics with an inert carbon–carbon (C–C) backbone, such as polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC), are the most widely used types of plastic in human activities. However, many these polymers were directly discarded nature after use, few appropriately recycled. This not only threatens natural environment but also leads to waste carbon resources. Conventional chemical recycling plastics, including pyrolysis catalytic cracking, requires a high energy input due inertness C–C bonds C–H complex product distribution. In recent years, significant progress has been made development catalysts introduction small molecules additional coreactants, which could potentially overcome challenges. this Review, we summarize highlight strategies that address issues upcycling backbone plastics molecules, particularly heterogeneous catalysis. We believe review will inspire methods for using

Language: Английский

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Optimizing the Electronic Structure of IrO_x Sub-2 nm Clusters via Tunable Metal Support Interaction for Acidic Oxygen Evolution Reaction

ACS Catalysis, Journal Year: 2025, Volume and Issue: 15(3), P. 1942 - 1951

Published: Jan. 17, 2025

Iridium-based electrocatalysts are the most promising candidates for acidic oxygen evolution reaction (OER). Considering their high cost and scarcity, it is imperative to maximize atom utilization enhance intrinsic activity of iridium. In this work, IrOx sub-2 nm clusters stabilized on TiO2 supports via metal support interaction (MSI) induced by vacancy defects in TiO2. The strength MSI readily tuned type vacancies: vacancies (VO-TiO2) induce adsorbed with relatively weak strength, while titanium (VTi-TiO2) lead strong embedded MSI. tunable further modulates electronic structure clusters. IrOx/VO-TiO2 exhibits an optimized a downshifted d-band center IrOx, resulting reduced binding energy low barrier rate-determining step OER. Consequently, delivers twice that commercial IrO2 good stability 120 h practical proton exchange membrane water electrolyzer. Our study provides guideline rational design OER catalysts based modulating

Language: Английский

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Effective Methane Suppression in Upcycling of Polyethylene into Fuels via Alloying Platinum with Ruthenium Supported on ZSM-5 Zeolite

Nano Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 13, 2025

Ruthenium (Ru)-based catalysts are active in catalyzing polyethylene (PE) upcycling, but their tendency for methanation devalues the process. Although previous works confirmed that regulation of Ru structure can inhibit methane yields, mechanism is still unclear, and catalytic performance remains higher upside potential. Herein, we synthesized M-Ru/H-ZSM-5 (M = Pt, Pd, Rh) PE upcycling. Pt-Ru/H-ZSM-5 had better conversion (84.36%) liquid fuel selectivity (78.38%) extremely low (8.43%), which be ascribed to its more electron-deficient Ruδ+ species synergistic effect induced by Pt doping. Through density functional theory calculations, nature inhibition was uncovered reaction pathway proposed. Furthermore, catalyst demonstrated stability reusability, as well efficacy upcycling various PEs. This work reveals Ru-based reactions, promoting plastic recycling development.

Language: Английский

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Precise activation of C–C bonds for recycling and upcycling of plastics

Chemical Science, Journal Year: 2023, Volume and Issue: 15(3), P. 795 - 831

Published: Dec. 8, 2023

The critical task of activating and cleaving inert C–C bonds during plastic upcycling recycling holds substantial importance.

Language: Английский

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