ChemSusChem最新文献

A novel series of bio-based cationic surfactants, synthesized from the platform chemical 5-(hydroxymethyl)furfural (5-HMF), fatty acids, and bio-based amines, has been developed, offering a sustainable alternative to conventional surfactants. These compounds, referred to as surface-active ionic liquids (SAILs), have critical micelle concentration (CMC) values lower compared to conventional quaternary ammonium cationic surfactants, indicating enhanced surface activity. The surface properties of the SAILs are predominantly influenced by the type of substitution in the cationic head group, with morpholinium-based surfactants having significantly lower CMC values than diethyl ammonium ones. The length of the alkyl chain also plays a significant role in determining the physicochemical and biological characteristics of these surfactants, which vary depending on the chain length. Surfactants with longer alkyl substituents demonstrate enhanced thermal stability and surface activity. The newly synthesized amphiphiles exhibit antimicrobial activity comparable to known quaternary ammonium cationic agents but with lower cytotoxicity. Importantly, these surfactants show controlled degradation under temperature-driven hydrolysis and basic conditions while maintaining stability in acidic environments. These findings highlight the potential of developed bio-based surfactants to deliver high performance with reduced environmental impact, positioning them as potential candidates for antimicrobial applications and industrial uses focusing on sustainability goal.

Polypropylene separators (PP) are widely used in lithium-ion batteries due to good electrochemical stability and low cost. However, PP separators are prone to thermal shrinkage at high temperatures, resulting in short circuit of positive and negative electrode contacts and thermal runaway. In this work, a waterborne core-shell emulsion binder rich in carboxyl and ester groups with both strength and adhesion is designed and coated with alumina (Al2O3) as a composite coating on the PP separator. Due to the good adhesion of the emulsion binder to the Al2O3 and the PP separator, the separator has excellent dimensional stability at 120 °C, while the thickness of the separator only increases by 2.5 μm. With the help of the dissociation effect of the ester group on the lithium salt and the lithium ion conduction characteristics, the composite separator improves the ionic conductivity (0.82 mS/cm) by 25 % compared with the PP separator and the lithium ion transference number reaches 0.47. The cycling capacity of the lithium-ion battery with the composite separator is 8.62% higher than that of the PP separator after 100 cycles. The performance changes of acrylic acid as a functional monomer on emulsion binders and composite separators are further investigated.

Electrochemical CO2 conversion to high-value chemicals and fuels has been extensively investigated as a promising carbon-neutrality technology. To date, most studies are generally performed with pure or highly concentrated CO2 feeds, however the composition of industrial flue gases is very complex, with a low CO2 concentration and impurities like O2, CO, NOx, and SOx. Direct utilization of industrial flue gases can bypass the capture and purification steps, yet it suffers from multiple challenges. In this Concept article, we discuss scientific challenges and innovation strategies towards direct electrochemical conversion of CO2 from industrial flue gases. Selected examples on rationally designing catalytic materials and electrode structures for promoting electrochemical reduction of CO2 in the presence of N2 and impurity gases are highlighted. We end up the article with perspectives on the research opportunities and future directions in this emerging yet practical field.

The Cover Feature illustrates an anion-exchange membrane water electrolyzer (AEMWE) containing porous organic polymers (POPs) as particle-based ionomers. AEMWEs are fundamental to the sustainable production of green hydrogen from electricity generated by renewable sources because they use water as the sole feedstock. We present here a new class of low-cost particulate ionomers based on piperidone-derived POPs, which exhibit outstanding electrochemical properties, remarkable alkaline stability, and durability of over 500 hours at a current density of 0.5 A cm⁻². More information can be found in the Research Article by A. E. Lozano, Y. M. Lee and co-workers.

Hydrodechlorination of poly(vinyl chloride) (PVC) directly to polyethylene (PE) represents a way to repurpose PVC waste, while avoiding toxic and/or corrosive byproducts that are produced at the end of life. Prior studies identified a rhodium-catalyzed route to hydrodechlorinate PVC to form PE products with sodium formate as a hydrogen source. While all chlorine could be removed to form PE-like polymers, the reaction was slow and side reactions introduced undesirable cross-links in the polymer product. In this work, mechanistic studies are pursued to improve catalytic activity for this method. Xantphos and diphenylphosphinoethane (DPPE) both support Rh(I) to promote this reaction to full conversion, effectively removing all chlorine from PVC samples, with Xantphos support providing the fastest metal catalysis for hydrodechlorination to date. However, side reactions to form cross-links are present for both catalyst systems. Control studies suggest the proposed route for cross-link formation also deactivates the Rh catalyst, indicating the cross-link formation can also be the cause for the reaction to slow over time. Other reaction conditions were found to influence the selectivity between hydrodechlorination and cross-link formation. These results introduce key catalyst design principles to improve methods for hydrodechlorination of PVC, allowing for sustainable repurposing of this toxic polymer waste.

The Cover Feature shows the in-situ product removal (ISPR) of monomers produced from the enzymatic depolymerization of poly(ethylene terephthalate) (PET) by using a membrane reactor, which leads to less caustic solution for pH maintenance, higher enzyme concentrations within the membrane, and increased PET depolymerization. This improves the environmental friendliness and energy efficiency of the process and addresses the pressing need for more sustainable solutions for plastic recycling. More information can be found in the Research Article by H.-W. Wong and co-workers.

The Front Cover introduces the Crab-Mill, portraying in an artistic manner the process of chemically upgrading renewable chitin-derived furans through milling. Embracing many principles of sustainability, this method utilises mechanochemistry—an emerging technology offering a more environmentally friendly alternative to solution-based synthesis. The hexagonal lights represent the functionalised pharmaceutically relevant nitrogenated aromatics produced in this work, specifically (4-acetyl)aminophthalimides, which exhibited fluorescence when exposed to UV light. More information can be found in the Research Article by D. L. Browne, J. C. Pastre and co-workers.

The Cover Feature shows the different reactivity of electron-rich Fe^III-superoxo and electron-deficient Fe^III-superoxo formed upon the binding of O₂ on Fe porphyrins. The former can undergo smooth protonation, but the latter requires further reduction at more cathodic potentials to give Fe^III-peroxo for protonation. This reactivity difference of Fe^III-superoxo leads to the different catalytic O₂ reduction behaviors of Fe porphyrins. More information can be found in the Research Article by R. Cao and co-workers.

Perovskite/perovskite/silicon triple-junction tandem solar cells (TSCs) hold significant potential for achieving higher efficiencies while lowering the levelized cost of electricity. The top subcell utilizing wide-bandgap (WBG) perovskite is crucial for improving the efficiency of TSCs. However, the defects caused by poorly crystallized WBG perovskite films and suboptimal energy level alignment lead to significant energy loss. Herein, we present a multifunctional interface engineering utilizing piperazinium bromide (PZBr) for enhancing the property of 2.03-eV perovskite films. The unique molecular structure of PZBr enables it to effectively passivate defects in perovskite films, to suppress photoinduced phase segregation, and to improve the energy band alignment between perovskite films and contact layers. Additionally, the PZBr modification facilitates the crystal ripening process in perovskite polycrystalline films. These functions result in suppressed non-radiative recombination and accelerated carrier extraction. Consequently, single-junction 2.03-eV perovskite solar cells (PSCs) achieved a remarkable efficiency of 13.82%, one of the highest efficiencies reported for PSCs with a bandgap exceeding 2.0 eV. In further, a monolithic triple-junction TSC was fabricated, achieving a photovoltage of 2.96 V and a champion efficiency of 20.05% (aperture area: 1 cm2). This work underscores the critical role of PZBr-based interface engineering in advancing WBG PSCs and triple-junction TSCs.

Chemical recycling of polymer waste is a promising strategy to reduce the dependency of chemical industry on fossil resources and reduce the increasing quantities of plastic waste. A common challenge in chemical recycling processes is the costly downstream separation of reaction products. For polybutylene succinate (PBS) no effective recycling concept has been implemented so far. In this work we demonstrate a promising recycling concept for PBS, avoiding costly purification steps. We developed a sequential process, coupling enzymatic hydrolysis of PBS with an electrochemical reaction step. The enzymatic step efficiently hydrolyses PBS in its monomers, succinic acid and 1,4-butandiol. The electrochemical step converts succinic acid into ethene as final product. Ethene is easily separated from the reaction solution as gaseous product, together with hydrogen as secondary product, while 1,4-butandiol remains in the aqueous solution. Both reaction steps operate in aqueous solvent and benign reaction conditions. Furthermore, the influence of electrolyte components on the electrochemical step was unraveled by applying molecular dynamic simulations. The final coupled process achieves a total ethene productivity of 91 µmol/cm2 over a duration of 8 hours, with 1110 µmol/cm2 hydrogen and 77% regained 1,4-butandiol as valuable secondary products.