Green Chemistry最新文献

The Baeyer–Villiger oxidation represents a valuable reaction that enables the conversion of ketones into esters or lactones. Here, we present a novel and efficient approach utilizing I₂ as a catalyst for the oxidative rearrangement of cyclobutenones, resulting in the synthesis of furan-2(5H)-one. Notably, this method employs dimethyl sulfoxide (DMSO) as a greener oxidant and source of oxygen. The reaction proceeds smoothly with catalytic amounts of iodine, yielding lactones in good yields. Compared to conventional Baeyer–Villiger oxidation reactions that rely on peroxyl acids or hydrogen peroxide, the use of DMSO offers a safer and more versatile alternative.

Porous hollow spherical particles benefit from special structural features and fascinating physicochemical properties resulting in widespread application. Particularly in pharmaceutical engineering, they have significant advantages for direct compression and drug combination. However, their large-scale application is severely hindered by the limitations of traditional production methods in terms of the use of complex equipment, high energy consumption and high organic solvent usage. In this work, we have developed an oiling-out directional agglomeration method to produce porous hollow indomethacin spherical particles by a simple heating–quenching–drying operation without the use of organic solvents and templating agents. Compared to commercial flake crystals, the indomethacin spherical products have higher average tensile strength (471% increase) and higher plastic deformability, i.e. better tabletability and compressibility. More importantly, nifedipine is successfully loaded into porous hollow indomethacin spherical particles based on molecular polarity differences. The composite particles with a core–shell structure exhibit excellent powder properties, tableting and anti-degradation performance, while also achieving sequential release of drugs. This contribution provides the basis for the development of drug formulation strategies and the design of functional crystalline materials.

The harmless disposal and resourceful recovery of spent lithium-ion batteries is an inevitable choice to protect the environment, conserve resources and promote the development of the circular economy. A systematic, green, and sustainable recycling process for waste LiFePO₄ batteries is proposed based on malic acid. The method employs naturally degradable organic acids instead of traditional inorganic acid leaching, reducing the negative impact on the environment. Under optimized conditions, 99.12% Li is extracted, while less than 1% Fe is leached. This fraction of iron ions is cleverly employed as a catalyst to promote the leaching efficiency of lithium. Furthermore, the iron by-products from the purification process are used for As(III) adsorption and show surprising arsenic removal properties. A minor amount of P in the leachate is recovered as Li₃PO₄, and most Li is collected as Li₂CO₃ with 99.63% purity. Ultimately, the LiFePO₄ cathode material is regenerated from the obtained Li₂CO₃ product and FePO₄ residue. Compared with the traditional method, this process merits efficient lithium–iron separation, environmental friendliness, and economic efficiency.

An atom- and step-economical, efficient and eco-friendly method for constructing naphthoselenazol-2-amines through a visible-light photocatalytic multi-component reaction under aqueous phase conditions is reported. This visible-light-induced reaction proceeded at room temperature under exogenous photosensitizer- and additive-free, neutral and mild conditions with low-cost and abundant elemental selenium as the selenium source, ambient air as the clean oxidant and pure water as the sole solvent.

Solar-driven steam generation (SSG) systems for sustainable clean water desalination and purification through photothermal conversion have been widely studied. Integrating solar-driven electricity generation (SEG) including hydroelectricity, saline electricity, moisture electricity, and thermoelectricity during the evaporation process is an effective way to utilize energy comprehensively. Carbon materials with superior stability, processability, practicability, abundance, and cost-effectiveness have aroused tremendous attention in the solar-driven steam and electricity generation (SSEG) field. Carbon materials can simultaneously play the essential role of solar absorbers for energy harvesting and conductive substrates for energy generation during SSEG. In this review, energy harvesting and generation mechanisms of carbon materials with different dimensions are first introduced. Afterward, the hybrid evaporation-induced electricity generation devices including hydroelectricity, saline electricity, moisture electricity, and thermoelectricity, and relevant efficiency-improving strategies are demonstrated. Moreover, the potential applications in power supply, energy storage, and electrical sensors are also discussed. Finally, some remaining challenges are considered, and suggestions for future development are sincerely proposed.

The concept of electrosynthesis, which enables single electron reduction without relying on expensive catalysts, has captivated the attention of both academic and industrial researchers. In our pioneering work, we delve into the realm of this promising methodology by presenting a remarkable application of the cross-coupling of redox-active esters with nitroarenes utilizing sacrificial metal anodes. This innovative approach empowers the synthesis of high-value products from readily available and economically viable starting materials. By harnessing the power of electrosynthesis, we not only achieve efficient transformations but also contribute to the sustainability and accessibility of valuable chemical synthesis.

Esterification is an important reaction mechanism for the conversion of many bio-based molecules. In this work, we study the esterification of bio-based diols isosorbide and isomannide with different short-chain organic acids via two well-established esterification routes. Route 1 is Fischer esterification, i.e. it is catalytic and uses an organic acid as a reaction partner. Route 2 uses a more reactive acid anhydride instead of free acids, and therefore, it is faster and does not require a catalyst and entraining agent. A comparative cradle-to-gate life cycle assessment was conducted to identify the ecological advantages and disadvantages of each esterification route in order to conclude on their greenness and identify points for future improvement. It was found that Route 1 consumes around 30% less energy for the production of the reactants and auxiliaries compared to Route 2. However, Route 2 requires only 10% of the energy for the esterification process because of the much shorter reaction time (3 h) than that of Route 1 (30 h). Since the current global energy source mix is largely fossil-based, impacts related to emissions from energy production dominate the ecological impacts of both routes and scale with the total energy demand. Therefore, Route 2 is currently the greener one in most impact categories (global warming, fossil depletion and human toxicity potential) with the exception of a high water depletion potential (WDP), which is related to the acid anhydride production. If in future only renewable energy from sun, wind and water was used for ester production, both esterification routes would be much greener. With the current global energy mix, the greenness of Route 1 could be enhanced if the reaction time could be shortened, a well reusable catalyst could be found and if the recycling rate of the entrainer and excess acid could be further increased or their amount generally reduced.

Lignin valorization is indispensable for a green biorefinery. Enzymatic depolymerization using ligninolytic enzymes, like manganese and lignin peroxidases, is a promising approach. However, enzymatic depolymerization performed in a batch system is hindered by a repolymerization reaction. Here, we successfully enhanced the lignin depolymerization efficiency by performing peroxidase-catalyzed depolymerization of beech wood lignin in a recently reported membrane bioreactor, in which water-soluble lignin fragments are continuously passed through a membrane. The total amount of water-soluble lignin fragments using the membrane bioreactor turned out to be maximally 28-fold higher than that with a batch bioreactor. GC-MS analysis showed the presence of a variety of short aliphatic and aromatic compounds as constituents of the water-soluble lignin fragments. Furthermore, lignin quantification and SEC analyses of the remaining solid residue in the membrane bioreactor indicated a higher degree of lignin depolymerization and removal. Semi-quantitative NMR analysis also supported the effective lignin removal in the membrane bioreactor. These findings demonstrate the effectiveness of the membrane bioreactor for the enhancement of native lignin depolymerization and removal by peroxidases.

Investigation of catalytic hydrogenation of CO₂ to CO via the reverse water–gas shift (RWGS) was undertaken using Ni/SiO₂-based catalysts. Among the array of catalysts tested, the Ni/SiO₂ catalyst derived from the reduction of silicalite-1-encapsulated, ligand-protected Ni²⁺ (Ni_0.2@S-1-red) exhibited promising performance. This catalyst demonstrated a CO₂ conversion rate approaching the equilibrium conversion of RWGS, a selectivity for CO exceeding 99%, and a high space time yield of CO (9.7 mol g_Ni⁻¹ h⁻¹). The outcomes observed can be attributed to several factors, such as the highly dispersed Ni⁰ and Ni^δ+ species, as well as the presence of bridging oxygen of the Ni–O–Si structure, on which CO₂ can be adsorbed moderately. The moderately bonded CO₂ on Ni_0.2@S-1-red allows for the efficient desorption of its reduced intermediate, i.e. *CO, resulting in the generation of gaseous CO at a rapid rate, consequently preventing its deep hydrogenation to CH₄. Complementary Density Functional Theory (DFT) calculations were performed and revealed that CO molecules have poor adsorption and higher adsorption energy on the Ni@S-1 surface compared to the S-1 surface. This supports the rapid desorption of *CO and the observed high selectivity of CO. Moreover, the structure–activity correlation analysis further supports the claim of Ni_0.2@S-1-red as a promising RWGS catalyst.

In this work, blue applicability grade index (BAGI) is proposed as a new metric tool for evaluating the practicality of an analytical method. BAGI can be considered complementary to the well-established green metrics, and it is mainly focused on the practical aspects of White Analytical Chemistry. This tool evaluates ten main attributes including the type of analysis, the number of analytes that are simultaneously determined, the number of samples that can be analyzed per hour, the type of reagents and materials used in the analytical method, the required instrumentation, the number of samples that can be simultaneously treated, the requirement for preconcentration, the automation degree, the type of sample preparation, and the amount of sample. Through the evaluation of these attributes, an asteroid pictogram is generated, together with the respective score. To facilitate the use of the metric a simple, open-source application was created (mostwiedzy.pl/bagi). It is accompanied by a web application available at bagi-index.anvil.app. The functionality of the tool was demonstrated by evaluating the applicability of five different analytical methods as case studies. All things considered, BAGI can be easily used to identify the weak and strong points of a method in terms of practicality and applicability, as well as to compare the performance of different analytical methods. We believe that BAGI metric tool will gain not only attention but also trust and acceptance from the chemical community.