ChemSusChem最新文献

Polylactic acid is currently the most widely produced biodegradable polyester plastic. However, its conventional disposal methods such as natural degradation, composting, and incineration not only generate substantial CO₂ emissions but also result in significant resource loss. In contrast, upcycling technologies can transform plastic waste into high value-added chemicals, offering considerable application potential in producing renewable monomers for new polymers, sustainable fuels, and value-added fine chemicals for the pharmaceutical and chemical industries. In this study, we fabricated a self-supported NiCo bimetallic oxides (NiCoO_x/NF) electrode via an electrodeposition strategy for the electrocatalytic upcycling of PLA wastes. Owing to the abundant exposure of active sites and efficient electron transfer between bimetallic species, the electrode exhibited excellent electrocatalytic performance, enabling the electrocatalytic reforming of PLA hydrolysates into acetate with Faradaic efficiencies exceeding 90% in the potential range of 1.32–1.52 V. In situ characterizations identified pyruvate and CH₃CO- as key intermediates mediating the formation of acetate. Furthermore, techno-economic analysis demonstrated the scalability and profitability of this approach. This work provides a novel and sustainable pathway for the green and efficient utilization of PLA wastes.

The continuous accumulation of postconsumer polyesters has caused a severe environmental and ecological crisis. Chemical recycling provides a promising strategy for transforming polyester waste back to monomers and value-added chemicals with improved energy efficiency. Herein, we report a chemical recycling of polyesters via the white-light-induced vanadyl catalysis at room temperature (without external heating; 25°C–50°C under irradiation). Mechanistic studies demonstrated the dual roles of the vanadyl photocatalyst in both bond activation and hierarchical structural disintegration. The protocol is highly compatible with 27 examples of polyethylene terephthalate (PET)-based materials, even reinforced packaging containers and colored composite textiles, affording terephthalic acid (TPA) monomer with up to quantitative yields. A 100 g-scale experiment further demonstrated the robustness and feasibility of the process as a practical strategy for PET waste valorization.

Photocatalytic conversion of biomass-derived platform molecules provides a promising route to store intermittent solar energy as clean chemical energy, enabling the sustainable production of high-value chemicals from abundant, low-cost biomass. However, achieving high selectivity and conversion efficiency remains challenging due to the inherent complexity of multistep interfacial reaction pathways. This review concludes recent advances in mechanistic investigations that encompass all crucial processes, including active species evolution, intermediate transformation, charge transfer, and chemical bond cleavage/reformation, employing advanced experimental methods, including electron paramagnetic resonance spectroscopy, radical quenching, isotope labeling, and in situ Fourier transform infrared spectroscopy. The applicability, sensitivity, and limitations of these techniques are critically evaluated across diverse reaction environments. Finally, we outline key challenges, such as limited temporal resolution, and discuss prospects for integrating complementary operando techniques with data-guided mechanistic modeling.

Molecular engineering of self-assembled hole transport monolayer (SAM) has been proven as a crucial way to improve the performance of perovskite solar cells (PSCs). We report a thiophene-based conjugated SAM (MPA-Th-CA) for PSC through rational design to exploit superior conjugation and heteroatom effects. This SAM delivers multifaceted enhancements over its benzene-based counterpart (MPA-Ph-CA), featuring a larger dipole moment, improved conductivity, optimized energy level alignment with perovskite, more uniform substrate coverage, and promoted perovskite crystallization. Ultimately, devices based on MPA-Th-CA achieved an excellent power conversion efficiency of 25.53% and demonstrated markedly improved stability under long-term operation, high humidity, and high-temperature conditions. This work provides an important strategy for optimizing interfacial materials via conjugated molecular design to fabricate high-efficiency, stable PSCs.

Polyurethane (PU) is a widely utilised plastic material due to its versatile properties. The chemical recycling, especially by hydrothermal treatment, is an effective way to achieve the circular use of PU. This article reports the results of hydrothermal treatment of PU with and without the use of acidic and basic catalysts. Both non-catalytic and catalytic approaches showed that PU could be depolymerised to the monomers using hydrothermal treatment. The use of a catalyst improved PU conversion and 2,4-toluenediamine (TDA) yield. An organic amine showed better catalytic activity than inorganic base NaOH, inorganic acid H₂SO₄, and organic acid acetic acid. Among the catalysts tested, the organic amine ethylenediamine exhibited the highest activity, achieving a TDA yield of 13.6 wt% and a PU conversion of 28.2% at 180°C. Organic bases outperformed inorganic acids and bases, such as H₂SO₄, acetic acid, and NaOH, which is attributed to their ability to form ionic interactions with PU-derived zwitterions and their uniform distribution across vapour and liquid phases under vapour–liquid equilibrium.

Polycarbonate acrylonitrile butadiene styrene (PC/ABS) is one of the most widely used plastic blends, with growing importance in both automotive and electronics applications. However, its heterogeneous nature disables recycling, leading to its disposal via landfilling or incineration. This work proposes a way to recycle this material via selective chemical recycling whereby the PC is depolymerized by acetolysis, heating the blend with acetic acid and a basic organocatalyst, leaving the ABS untouched. Catalytic optimization on PC feedstocks revealed that successful organocatalysts required not only sufficient basicity but also a basic nitrogen incorporated within an aromatic ring. A kinetic study revealed the depolymerization was pseudo first-order with an activation energy of 96.7 kJ mol⁻¹. Selective acetolysis was developed for both PC/ABS pellets and a PC/ABS automotive part. Separation of the PC monomers from the ABS was achieved with dialysis, with isolated ABS having similar properties to virgin grades. This approach offers a promising route toward recovering value from recalcitrant PC/ABS blends by enabling selective deconstruction of PC and recovery of ABS, thereby minimizing dependence on virgin plastic production.

Conventional chemical recycling of polyethylene terephthalate (PET) via glycolysis is hindered by the high energy cost of separating water and ethylene glycol (EG) via distillation. In this work, the energy-intensive EG-water separation step was excluded by implementing a water-free, membrane-based process for the production and purification of bis(2-hydroxyethyl) terephthalate (BHET) from PET glycolysis. The proposed approach is built upon three key innovations: (1) a micro-sized MgO/SiO₂ heterogeneous catalyst that enhances PET depolymerization efficiency, achieving a 95.1% BHET yield, (2) a water-free glycolysis process that reduces process complexity, and (3) an organic solvent nanofiltration-based purification and concentration strategy that selectively separates BHET while minimizing energy-intensive phase-change operations. A high overall BHET yield of 93.2% was achieved, enabled by a two-stage cascade concentration with over 99% yield. Compared to conventional distillation, the proposed process reduces energy consumption by 86%. Techno-economic analysis revealed a return on investment of 2.48 years for a production capacity of 1000 tons of BHET per day, highlighting its economic viability. By minimizing reliance on phase-change operations, this process presents a scalable and transformative solution for sustainable chemical recycling, serving as an important stepping stone to transform PET glycolysis from a batch to a continuous process.

Copper-based catalysts offer promise for CO₂-to-C₂₊ conversion but suffer from instability of Cu⁺ species, which are active sites critical for enabling C−C coupling. In this work, we synthesized Lanthanum (La)-doped Cu_xO (La-Cu_xO) catalysts with varying La/Cu ratios to investigate how the interplay between doping-induced electronic effects and grain boundary (GB)-driven stabilization affects deep CO₂ reduction to C₂₊. Combined density functional theory calculations and in situ spectroscopic characterization reveal that the unique 4f orbital configuration and strong Lewis acidity facilitate charge transfer of La, stabilizing Cu⁺ during CO₂ reduction reaction (CO₂RR), while simultaneously inducing lattice distortion to increase GB density. This modulation preserves Cu⁺/Cu⁰ interfaces while enhancing *CO dimerization kinetics. Furthermore, La doping boosts *CO coverage at GB-rich regions and lowers the C−C coupling barrier. The optimized La-Cu_xO-2 catalyst (La/Cu = 0.224) achieves a 45.2% C₂H₄ Faradaic efficiency (FE) and 75.4% C₂₊ FE at −0.8 V_RHE, with partial current densities of 87.5 and 146.7 mA cm⁻², respectively, surpassing undoped Cu_xO. Remarkably, it retains more than 90% initial activity after 24 h operation, demonstrating exceptional stability. This work provides a rational strategy for stabilizing Cu⁺ and tailoring pathways via rare-earth doping.

All-perovskite tandem solar cells (TSCs) have recently surpassed the 30% power conversion efficiency milestone, positioning mixed tin-lead (Sn-Pb) perovskite as indispensable narrow-bandgap absorbers. Their optimal bandgap, reduced lead content, and solution processability make them promising for next-generation photovoltaics. However, their widespread application is hindered by severe stability issues, primarily the facile oxidation of Sn²⁺ and crystallization mismatch between Sn- and Pb-based phases. Distinct from existing reviews, this short review provides an integrated framework for the two fundamental bottlenecks of Sn-Pb perovskite-Sn²⁺ oxidation and Sn/Pb crystallization mismatch-linking mechanistic insights across precursor chemistry, thin-film formation, and device operation. We summarize recent advances that enable efficiencies >23% together with thousand-hour operational stability, and we outline future directions toward fully integrated, scalable, and commercialization-relevant stability solutions.

Solid oxide electrolysis cells (SOECs) are among the most efficient energy-conversion devices for power-to-X applications in green energy technologies. Here, we report a high-level (5 mol%) Li- and Co-dual-doped gadolinium-doped ceria (GDC) electrolyte synthesized under an inert atmosphere, suitable for fabricating SOECs using conventional ferritic steel supports. The doped GDC exhibits uniform dopant incorporation and a single-phase cubic fluorite structure, achieving 98.18% relative density at 950 °C. Dilatometry and microstructural analyses reveal that Li-Co codoping significantly reduces sintering temperature and improves grain connectivity. Time-of-flight secondary ion mass spectrometry shows a Li,Co-rich surface layer whose thickness depends on sintering conditions, while Raman spectroscopy confirms the presence of a LiCoO₂ phase and temperature-dependent oxygen-vacancy concentration. Electrochemical impedance spectroscopy demonstrates enhanced ionic conductivity, particularly for the sample sintered at 950 °C (denoted 5LC-4), which achieves increases of 269.5% at 450 °C and 138.85% at 750 °C compared with commercial GDC. The ionic conductivity reaches 2.17 × 10^-2 S cm^-1 with an activation energy of 0.32 eV. A symmetric five-layer SOEC integrating 5LC-GDC exhibits superior electrochemical performance to yttria-stabilized zirconia (YSZ) support, achieving a peak power density of 267.5 mW cm^-2 at 850 °C.