ChemSusChem最新文献

Diols are versatile starting materials for preparing a series of value-added products. However, the biocatalytic oxidation of diols to hemiacetals remains challenging, primarily due to the inherent instability of hemiacetals in aqueous media. Herein, we report the use of unspecific peroxygenases for the mild and selective oxidation of diols into hemiacetal products. Based on the concept of reaction engineering, this catalytic process was performed under neat reaction condition using immobilized enzymes. This unique reaction system allowed a variety of patterned diols being converted into the stable hemiacetal products with chemoselectivity up to 99%. By optimizing the reaction conditions, the hemiacetal products were converted in situ to lactones, thereby further broadening the application of diol oxidation reactions. The molecular modeling of the enzyme–substrate interaction sets up a basis for the mechanistic understanding of the reaction activity and selectivity. This work demonstrated a new approach of transforming diols into synthetic building blocks by unspecific peroxygenases.

Covalent grafting of S-containing ligands onto a zeolitic imidazolate framework (ZIF) can create a material with enhanced metal capture capabilities. This is achieved by forming thiazolidine groups from the condensation of aldehyde groups from the imidazole linker with cysteine, which can act as binding sites for noble metal ions. The ZIF material provides a highly porous support that controls the growth of metal nanoparticles, while the thiazolidine groups offer specific interactions with the noble metal atoms, leading to superior loading and minimal metal leaching.

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS, AI 4083), is by far the most widely employed hole transport layer (HTL) material, but still suffers from drawbacks of high acidity and strong hydrophilicity, which hamper the device stability in organic solar cells (OSCs). To address these limitations, we designed and synthesized a novel CF₃-containing sulfonated copolymer (PSF) counterion and incorporated it with PEDOT to form the PEDOT:PSF complex, which has excellent solution and film stability. In this work, PSF combines a significant reduction of the acidity with a much decreased hygroscopic nature. When employed in OSCs with different active layers, namely PM6:Y6, PM6:BTP-eC9, PM6:L8-BO, and D18:L8-BO, the PEDOT:PSF-doped HTL delivered maximum power conversion efficiencies (PCEs) of 16.71%, 17.20%, 18.36%, and 18.55%, respectively, which are consistently slightly better than those achieved by comparable OSCs using PEDOT:PSS as HTL. Notably, this novel HTL displayed significantly enhanced stability and durability of devices; the doped and pristine PEDOT:PSF-based OSCs retained 83% and 71% of their initial PCE after 730 h of continuous illumination, whereas PEDOT:PSS devices retained merely 58%.

Waste glycerol, the main byproduct of biodiesel production, can be converted into value-added chemicals via electrocatalytic oxidation reaction, providing a promising pathway for green and sustainable energy development. This concept comprehensively reviews the development process of transforming glycerol from waste byproduct into value-added chemicals. Firstly, we outline the overall pathway of glycerol oxidation reaction and the applications of its product. Next, focusing on C1 and C2 products, we propose five key design strategies—doping, heterojunction, alloy, vacancy, and surface modification strategies to regulate the electronic properties of electrocatalysts and enhance catalytic activity. Additionally, for high value-added C3 products, we analyze for the first time the effects of environmental factors such as adsorption configuration, interface microenvironment, electrolyte effect, and pulse potential on GOR activity and C3 selectivity, providing an overview of recent advances. Finally, we highlight the current challenges in GOR and propose prospects to promote further industrial development.

The shuttle effect of polysulfides and the piercing of dendrites severely limit the cycling stability and safety of room-temperature sodium–sulfur (RT Na–S) batteries. To address these challenges, a sandwich structure separator was designed and prepared by electrospinning a fluorinated polyurethane copolymerized polyimide (PI-FPU) fiber membrane and assembling it on both sides of a commercial Celgard separator (PI-FPU/Celgard/PI-FPU). The external PI-FPU fiber layers synergistically suppress the polysulfide shuttle through the physical confinement combined with chemical anchoring. Meanwhile, the toughness of the PI-FPU membrane and the high mechanical strength of the Celgard substrate create a robust and flexible structure that effectively inhibits dendrite penetration. In addition, the inherent thermal stability and heat resistance of the PI-FPU material enhance the battery's resistance to thermal runaway and fire. Due to these advanced structural features, the sodium-symmetric cell with the PI-FPU/Celgard/PI-FPU separator achieves stable cycling for over 1000 h at a current density of 1 mA cm⁻². The assembled RT Na–S battery maintains a high discharge specific capacity of 555 mAh g⁻¹ after 1500 cycles at 3 A g⁻¹. This work provides a feasible strategy for developing high-safety and long-life RT Na–S batteries.

Polycarbonate (PC) ethanolysis using ionic liquids (ILs) offers an ecofriendly recycling method that enables the recovery of bisphenol A (BPA) without the need for newly synthesized BPA, a xenoestrogen used in PC polymerization. Depolymerization efficiency is strongly influenced by the structure of ILs. This study investigates the effect of the IL anion structure on the depolymerization efficiency by focusing on the role of hydrogen bond-donating functional groups. We examined the depolymerization performance and intermolecular interactions of three ILs (1-ethyl-3-methylimidazolium acetate [EMIM][Ac], 1-ethyl-3-methylimidazolium glycolate [EMIM][Ga], and 1-ethyl-3-methylimidazolium lactate [EMIM][La]). Among them, [EMIM][La] exhibited the highest depolymerization efficiency (100% PC conversion, 99.9% BPA yield, and 95% BPA purity) at 90°C for 8 h. This superior efficiency was attributed to the spatially accessible hydroxyl group of the lactate anion. Furthermore, [EMIM][La] maintained its catalytic activity during five consecutive recycling cycles, demonstrating its reusability. These findings could help design efficient IL catalysts for polymer depolymerization.

As a novel type of battery for energy devices, Li–CO₂ batteries have a slow kinetic reaction during carbon dioxide reduction and evolution, which leads to problems such as high battery polarization potential, poor cycling performance, and a short lifetime. Therefore, it is important to explore electrocatalysts with high activity and stability. In this study, a novel high-loaded single-atom catalyst was prepared by uniformly anchoring single-atom Ni/Co on N-doped carbon (NiNC/CoNC). Compared with previous reports, the doping amount of Ni is as high as 10 wt%. The Li–CO₂ battery assembled using NiNC achieves a high discharge capacity of 51,125 mAh g⁻¹ at 100 mA g⁻¹ current density and displays a low overpotential of 1.63 V after 268 stable cycles (more than 2600 h) at 200 mA g⁻¹ current density. The X-ray absorption fine structure analysis of NiNC reveals the presence of Ni and NiN₄ sites. Combined with density functional theory calculations, it is found that NiNC adsorbs CO₂ reactive species more strongly. Moreover, the electronic synergism of the NiN₄ sites can weaken the decomposition barrier of the discharge product Li₂CO₃ and accelerate the reaction kinetic process, thereby enhancing the electrocatalytic activities of CO₂ electroreduction and CO₂ reduction reaction.

Catalytic conversion of lignin to cyclic alkanes offers a promising route toward sustainable aviation fuel production. In contrast to the prevalent hydrodeoxygenation (HDO) of lignin oils for C6–C9 arenes and alkanes, here, we report an orthogonal approach for selective production of bicyclic alkanes (mostly C14 and C15 alkanes) from bisphenols isolated from arylated lignin oil. HDO of phenolic hydroxyl and methoxy groups in lignin bisphenols is promoted by heteropoly acid–metal catalyst synergy, favoring selective CO bond cleavage with minimal CC bond cleavage under moderate conditions.

Ethanol steam reforming with a water to ethanol molar ratio of 7:1 was investigated over pure ZnO and Al-doped ZnO catalysts with up to 10 mol% Al³⁺ synthesized via coprecipitation. This synthesis route yielded wurtzite ZnO, with Al being incorporated into the ZnO lattice at low doping levels. Al doping was found to alter the reaction pathway of ethanol steam reforming by suppressing the consecutive acetaldehyde conversion to acetic acid and further to acetone. Continuous kinetic experiments using a plug flow reactor resulted in almost full conversion and an acetone selectivity of 53% at 450°C over pure ZnO. Feeding acetaldehyde and acetic acid confirmed a consecutive multistep reaction network starting with ethanol dehydrogenation to acetaldehyde, followed by its conversion to acetic acid and a subsequent decarboxylative ketonization to acetone and CO₂. Upon Al doping, the specific surface area increased by about a factor of two, but conversion was hardly changed. Instead, the acetaldehyde selectivity increased, whereas acetone and CO₂ formation decreased, indicating that Al incorporation selectively suppresses ketonization. Overall, acetone formation via ethanol steam reforming was found to be a strongly structure-sensitive reaction over Al-doped ZnO, with its surface acid–base properties strongly depending on the Al content.

Electrocatalytic CO₂ reduction reaction (CO₂RR) converts atmospheric CO₂ into valuable chemicals using renewable energy. However, acidic CO₂-to-HCOOH electrolysis with high CO₂ utilization still faces challenges such as the competing hydrogen evolution reactions, acidic corrosion, and low selectivity. In this study, we synthesized a series of SnO₂ catalysts with tunable oxygen vacancy concentrations by high-temperature (300–900°C) calcination. The obtained SnO₂−600 catalyst achieved over 90% Faradaic efficiency (FE) across a wide current density range of −0.30 to −1.0 A cm⁻², with a peak FE of 96.2% at −1.0 A cm⁻², a formic acid production rate of 17.9 mmol h⁻¹ cm⁻². The catalyst could maintain 80% FE of HCOOH over 80 h. In situ Raman spectroscopy revealed that under CO₂RR conditions, the SnO₂−600 catalyst with moderate oxygen vacancies could convert to stable mixed-valence state SnO_x (Sn₂O₃ and Sn₃O₄) active species, while those without or excessive oxygen vacancies will be over-reduced. This study establishes a correlation between oxygen vacancy and acidic CO₂RR performance in Sn-based catalysts, highlighting mixed-valence SnO_x species as key active sites and providing a foundation for designing high-activity, stable CO₂RR catalysts for industrial applications.