Green Chemical Engineering最新文献

Lignin utilization is a potential approach for replacing fossil energy and releasing the environment pressure. Herein, we synthesized a series of novel Cu-based catalysts, Cu@NS-SiO₂ (NS = nano sphere) and alkali metals (Na, K, Rb, and Cs) doped Cu@NS-SiO₂, and applied them in hydrodeoxygenation reaction of anisole. High Cu dispersion was presented on all catalysts. The modification of alkali metals on Cu@NS-SiO₂ significantly enhanced the electron density of Cu sites in the following order: Cs > Rb > K > Na, among which Cs decreased the Cu 2p_3/2 binding energy most (by 0.7 eV). Moreover, the modification did not substantially affect the geometric structure of Cu species. This regulable electronic environment of Cu sites was crucial for selective deoxygenation and inhibiting the hydrogenation of aromatic rings in anisole, and thus promoted the selectivity of benzene. Compared with Cu@NS-SiO₂ (∼59%), the highest benzene selectivity was obtained on Cs/10Cu@NS-SiO₂ at ∼83%.

Electrochemical CO₂ reduction driven by renewable electricity is one of the promising strategies to store sustainable energy as fuels. However, the selectivity of value-added multi-carbon products remains poor for further application of this process. Here, we regulate CO adsorption by forming a Nafion layer on the copper (Cu) electrode that is repulsive to OH⁻, contributing to enhanced selectivity of CO₂ reduction to C₂₊ products with the suppression of C₁ products. The operando Raman spectroscopy indicates that the local OH⁻ would adsorb on part of active sites and decrease the adsorption of CO. Therefore, the electrode with repulsive to OH⁻ can adjust the concentration of OH⁻, leading to the increased adsorption of CO and enhanced C–C coupling. This work shows that electrode design could be an effective strategy for improving the selectivity of CO₂ reduction to multi-carbon products.

The coupling reaction of carbon dioxide (CO₂) and epoxides is one of the most efficient pathways to achieve the carbon balance. However, to accomplish it under the mild conditions, especially under the atmospheric pressure, is still a perplexing problem. Three novel ionic liquids (ILs), [DMAPBrPC][TMGH], [DMAPBrPC][DBUH], and [DMAPBrPC][BTMA], are designed and synthesized. All of them display the excellent catalytic activity for the title reaction achieving the yield over 96.6% under the atmospheric CO₂ pressure at 60 °C. Interestingly, [DMAPBrPC][BTMA] with the inert hydrogen atom in cation exhibits the superior catalytic activity as compared to other two ILs with the protic hydrogen atom in cation along with the same anion. The active hydrogen atom in [DMAPBrPC][TMGH] and [DMAPBrPC][DBUH] would impede the –COO⁻ group to absorb CO₂, which is an unfavorable item for the reaction. Moreover, the strong hydrogen bond in [DMAPBrPC][TMGH] and [DMAPBrPC][DBUH] would lessen the nucleophilic ability of Br⁻ anion resulting in the inferior catalytic performance, which is further confirmed by the density functional theory (DFT) calculations. The cation without the active hydrogen atom could also be employed to design the ILs with the excellent catalytic feature when it is combined with the suitable anion.

Dissolution of lithium cobalt oxide (LCO) is the key step for the recovery of valuable metals (e.g., Co and Li) from spent LCO-based lithium-ion batteries (LIBs). However, the dissolution process of LCO either needs toxic solvents, and high temperature, or shows low efficiency. Deep eutectic solvents (DESs) are potential green solvents to dissolve LCO. Here, DESs with polyethylene glycol (PEG) as hydrogen bond acceptor and ascorbic acid (AA) as hydrogen bond donor are found to dissolve LCO with 84.2% Co leaching efficiency at 80 ^oC and 72 h, which is higher than that from the reported references by common DESs. Furthermore, both DESs components (i.e., PEG and AA) are cheap, biodegradable, and biocompatible. AA could be easily and abundantly extracted from natural fruits or vegetables. It provides a new guide for the green, mild, and efficient dissolution of LCO aiming at sustainable recovery of spent LIBs.

Researchers prefer mild aqueous static zinc-ion batteries (ASZIBs) for their distinct benefits of excellent safety, abundant zinc resources, low cost, and high energy density. However, at the moment there are some issues with the cathode materials of mild ASZIBs, including dissolution, by-products, poor conductivity, and a contentious energy storage system. Consequently, there are numerous difficulties in the development of high-performance mild ASZIBs cathode materials. This overview examines the mechanisms for storing energy and the developments in inorganic, organic, and other novel cathode materials that have emerged in recent years. At the same time, three solutions—structural engineering, interface engineering, and reaction pathway engineering—as well as the difficulties now faced by the cathode materials of mild ASZIBs are forcefully introduced. Finally, a prospect is made regarding the evolution of cathode materials in the future.

Recently, the continuous tube-in-tube reactor based on the Teflon AF membrane is emerging as a powerful toolkit for accelerating gas-liquid mass transfer and reaction rate. Because of its large gas-liquid interfacial area and short mass transfer distance, the reactor can allow a fast gas-liquid mass transfer without direct contact between gas and liquid phases, offering an efficient and safe platform for implementing gas-liquid reaction and rapid determination of gas-liquid parameters. In this review, a detailed description and construction method of this reactor are provided. Then, the recent advancements of the tube-in-tube reactor in fundamental studies and practical applications in gas-involved chemical reactions and biosynthetic processes are discussed. Finally, a perspective on future potential applications of such flow reactors is provided.

A new ultra-long chain monounsaturated 4-(N-nervonicamidopropyl-N,N-dimethylammonium) butane sulfonate (NDAS) zwitterionic surfactant with ultralow interfacial tensions was developed through the modification of nervonic acid derived from renewable non-edible seed oils by a simple and effective method. Its structure was characterized by ESI-HRMS, ¹H NMR, and ¹³C NMR. NDAS surfactant exhibited a strong interfacial activity (∼10⁻⁴ mN/m) between the crude oil and the formation brine at a very low surfactant dosage (0.05 g/L) and at high salinity conditions, which is equivalent to 2% (w/w) of dosage of the most traditional surfactants used in the enhanced oil recovery field. Meanwhile, at a very low concentration (0.05 g/L), NDAS demonstrated strong NaCl compatibility up to 100 g/L, Ca²⁺ ions compatibility up to 200 mg/L, and temperature stability up to 90 °C. The surface tension, emulsification, and biodegradability parameters were also evaluated. This work consolidates our hypothesis that increasing the hydrophobic chain length of a surfactant certainly contributes to the high interfacial activity and good compatibility of salts and temperatures. Hence, it will facilitate the design of a sustainable alternative to petroleum-based chemicals to develop bio-based surfactants and extend the domain of bio-based surfactants to new applications such as in enhanced oil recovery (EOR).

Image guided photodynamic therapy (PDT) combines fluorescence tracing and phototherapy, which can achieve a more accurate and effective treatment effect. However, traditional photosensitizers are limited by the aggregation-caused fluorescence quenching (ACQ) effect and low reactive oxygen species (ROS) generation in a hypoxic environment, resulting in poor imaging and treatment effect. Herein, we report a tricyano-methylene-pyridine (TCM)-based Type I aggregation-induced emission (AIE) photosensitizer (TCM-MBP), the strong electron acceptance (D-A) effect extends the wavelength to near-infrared (NIR) region to reduce the autofluorescence interference, and oxygen atoms provide lone pair electrons to enhance the inter system crossing (ISC) rate, thereby promoting the generation of more triplet states to produce ROS. The AIE photosensitizer TCM-MBP exhibited low oxygen dependence, NIR emission, and higher ROS production compared to commercially available Ce 6 and RB. After encapsulation with DSPE-PEG₂₀₀₀, TCM-MBP nanoparticles (TCM-MBP NPs) could penetrate to visualize cells and efficiently kill cancer cells upon light irradiation. This study provides an oxygen-independent AIE photosensitizer, which has great potential to replace the commercial ACQ photosensitizers.