Green Chemical Engineering最新文献

Green synthesis of metal-organic frameworks (MOFs) in water with alleviated environmental influence and reduced cost is an essential step to transfer laboratory MOFs research to industrial application. Switching from the commonly used organic solvents to pure water encounters challenges of the poor solubility of organic linkers, slow reaction kinetics, and the formation of polymorphic products. So far, a universal MOFs synthetic strategy in water system has yet to be developed. This study reports the seed-aided synthesis of eleven MOFs with diverse compositions and structures while pure water serving as solvent. The corresponding reaction temperature and time of using this new strategy were reduced compared with original synthetic approaches, while the products maintain porous structure and high crystallinity. The success of this strategy relies on the addition of parent MOFs as seeds which could promote crystallization process by skipping the time-consuming induction period and avoiding the formation of polymorphic impurities.

The sustainable synthesis of dimethyl maleate via diesterification through the utilization of ionic liquid (IL) is of great importance. However, the relationship between the ILs nature and the reactivity of diesterification is still unclear. Herein, a series of ILs with different structures were selected for the comprehensive investigation of diesterification. The acidity (H₀) and Kamlet-Taft solvent parameters (hydrogen bond donor ability (α), hydrogen bond acceptor ability (β), and polarizability (π∗)) of ILs were measured by UV–Visible spectroscopy, and the effects of them on the diesterification of maleic anhydride were also studied in detail. The results indicated that not only H₀ of the IL-based catalysis system, but also its α, β, and π∗ influenced the reaction activity of diesterification. Furthermore, a quantifiable correlation was fitted between the natural logarithm of the rate constant and multiple parameters of ILs, indicating that the diesterification rate had a positive correlation with the H₀, α, and π∗, and inverse correlation with the β of the IL. A plausible synergetic reaction mechanism for the excellent performance of [(HSO₃)PMim][HSO₄] has been proposed. Overall, this work thoroughly explored the relationship between the nature of ILs on diesterification in-depth, which will reveal the nature of diesterification in detail.

One of the bottlenecks limiting the cycling stability of high voltage lithium metal batteries (LMBs) is the lack of suitable electrolytes. Herein, phenyl vinyl sulfone (PVS) is proposed as a multifunctional additive to stabilize both cathode and anode interfaces as it can be preferentially oxidized/reduced on the electrode surfaces. The PVS derived solid electrolyte interphase films can not only reduce the transition metal dissolution on the cathode side, but also suppress the Li dendrite spread on the lithium anode side. The Li||Li symmetric battery with PVS addition delivers longer cycle life and a higher critical current density of over 3.0 mAh cm⁻². The LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811)||Li full cell exhibits excellent capacity retention of 80.8% or 80.0% after 400 cycles at 0.5 C or 1 C rate with the voltage range of 3.0–4.3 V. In particular, the NCM811||Li cell under constrained conditions remains operation over 150 cycles. This work offers new insights into the electrolyte formulations for the next generation of LMBs.

Natural gas processing involves the separation of higher hydrocarbons (C2–C3) from methane, which is an important and energy-intensive operation. In this paper, we present a comprehensive study of an innovative copper-based MOF (Cu-MOF) for the separation of propane and ethane from methane. The material exhibits a high adsorption capacity and selectivity for C2–C3 hydrocarbons over methane, which is primarily due to its preferential C2–C3 hydrocarbon adsorption. The adsorption isotherms at ambient conditions showed a remarkable uptake of C₃H₈ of 134.0 cm³/g, as well as excellent selectivity of 204 and 9 for C₃H₈/CH₄ and C₂H₆/CH₄. According to the theoretical calculations, differences in van der Waals interactions and polarizability of the guest molecules were responsible for influencing separation performance. In addition, we conducted adsorption kinetic experiments, dynamic breakthrough, and cycling experiments to further examine the separation performance. Overall, this research establishes an energy-efficient adsorbent for upgrading natural gas.

Herein, the synthesis and characterization methods of natural deep eutectic solvents based on monoterpenoids have been presented. Low viscous fluids with suitable physicochemical properties are produced. The materials are non-toxic, biodegradable, and cost-effective. Thus, they can be used to develop sustainable solvents for various processes and can find their applications in various fields. A theoretical study based on quantum chemistry and classical molecular dynamics is used for the nanoscopic characterization of structure, dynamics, and hydrogen bonding. The reported results help analyze the properties of this new family of solvents. The required information for developing structure–property relationships for proper solvent design to form a sustainable chemistry framework is obtained.

Hydrogel microparticles, generally accepted as significant green materials, have been widely used in chemical, biological, and biomedical fields owing to their excellent biocompatibility, biodegradability, and non-cytotoxicity. Among these, non-spherical hydrogel microparticles with diverse shape anisotropy have great potential in applications such as drug delivery, cellular interaction, micromotors, etc. Benefiting from their shapes, their functionalities in such fields cannot be satisfied by the typical spherical types. Recently, microfluidics with precise control and domination of fluids at microflow sizes has emerged as a powerful method for synthesizing shape-controllable hydrogel microparticles with good monodispersity and unique morphology. In this review, we tried to provide an overview of the production of non-spherical microparticles composed of green hydrogel materials, emphasizing the microfluidic approaches. Furthermore, a brief introduction to their current applications is also presented.

Al₂O₃-supported monometallic Ni, Co, and bimetallic Ni–Co nanocatalysts originated from layered double hydroxide precursors were synthesized by co-precipitation method, and used for the synthesis of useful 5-amino-1-pentanol (5-AP) and 1,5-pentanediol (1,5-PD) by reductive amination (RA) or direct hydrogenation of biofurfural-derived 2-hydroxytetrahydropyran (2-HTHP), respectively. In both reactions, the yield of the target products decreased monotonously with the increasing amounts of Co in the NiCo/Al₂O₃ catalysts, owing probably to the replacement of highly reactive Ni by Co component with inferior hydrogenation activity at the low reaction temperature of 60 °C. However, the incorporation of Co could improve the reducibility of the NiCo/Al₂O₃ bimetallic catalysts and promote the reaction stability of the catalysts, especially for Ni₂Co₁/Al₂O₃, in both reactions with over 180 h time-on-stream. Characterization of the catalysts before and after the reaction showed that the incorporating Co could inhibit the sintering of metal particles and hinder the surface oxidation of the more reactive Ni⁰ species, thanks to the formation of Ni–Co alloy in the bimetallic catalysts. DFT-based modeling of the reaction mechanisms is also performed, supporting the reaction pathway proposed previously and also the much higher activity of Ni in the RA of 2-HTHP as compared with Co.

The highly efficient chemoselectivity, stereoselectivity, and regioselectivity render enzyme catalysis an ideal pathway for the synthesis of various chemicals in broad applications. While the cofactor of an enzyme is necessary but expensive, the conversed state of the cofactor is not beneficial for the positive direction of the reaction. Cofactor regeneration using electrochemical methods has the advantages of simple operation, low cost, easy process monitoring, and easy product separation, and the electrical energy is green and sustainable. Therefore, bioelectrocatalysis has great potential in synthesis by combining electrochemical cofactor regeneration with enzymatic catalysis. In this review, we detail the mechanism of cofactor regeneration and categorize the common electron mediators and enzymes used in cofactor regeneration. The reaction type and the recent progress are summarized in electrochemically coupled enzymatic catalysis. The main challenges of such electroenzymatic catalysis are pointed out and future developments in this field are foreseen.

A production technique with the high yield and environmentally friendly process need be developed for ε-Caprolactam (CPL) in the chemical industry. This technology is highly desired to design and synthesize high−performance catalysts for liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) to CPL. In this work, 3-methyl-1-(propyl-4-sulfonyl) imidazolium methanesulfonate ([PHSO₃MIM][MSA]) with highly efficient and excellent yield is synthesized successfully. When the optimum molar ratio of ZnCl₂ over [PHSO₃MIM][MSA] was 0.02, it exhibits the high selectivity (94%) of CPL at 90 °C for 1 h. Interestingly, Fourier-transform infrared (FT-IR) investigations show that the functional Brønsted−Lewis acidic types of ionic liquids (ILs) are formed by the uniformly distributed ZnCl₂ and [PHSO₃MIM][MSA]. In addition, the hydrogen bond (H-bond) is formed between CHO and ILs. After ten reaction cycles, no significant structure changes are observed in the recovered [PHSO₃MIM][MSA]·ZnCl₂. The solubilities of ILs are predicted by using COSMO-RS model, the results show that [PHSO₃MIM][MSA] is a promising candidate for the liquid phase Beckmann rearrangement of CHO into CPL. Finally, a theoretical model of the H-bond interactions between ILs and CHO is further confirmed to support the advance of reaction mechanism. A feasible way is provided for the CPL production technique in the liquid phase Beckmann rearrangement reaction.

When considering the usage of ionic liquids (ILs) for reactions and separations involving non-polar or weak-polar hydrocarbons, the knowledge of the mutual solubility behaviors of ILs and hydrocarbons is of the utmost importance. In this work, taking four typical C6-hydrocarbons namely benzene, cyclohexene, cyclohexane, and hexane as representatives, the mutual solubility of ILs and non-polar or weak-polar hydrocarbons are systematically studied based on the COSMO-RS model. The reliability of COSMO-RS for these systems is first evaluated by comparing experimental and predicted hydrocarbon-in-IL activity coefficient at infinite dilution and binary/ternary liquid-liquid equilibria of related systems. Then, the mutual solubility of the four hydrocarbons and 13,650 ILs (composed by 210 cations and 65 anions) are predicted. The effect of different IL structural characteristics including alkyl chain length, cation family/symmetry/functional group, and anion on the IL-hydrocarbon mutual solubility behaviors are further analyzed by the analyses of interaction energy and screen charge distribution. The mutual solubility databases and the structural effects identified thereon could provide useful guidance for IL selection in related applications.