Green Chemical Engineering
·
2022
·
IF 0
Qing Zeng,Shaonan Tian,Yu Zhang,Hui Liu,Dong Chen,Xinlong Tian,Chaoquan Hu,Jun Yang
Recycling precious metals with high-efficiency is undoubtedly beneficial to optimize resource utilization for environmental remediation and sustainable development. Herein, we report an efficient route to recycle the palladium (Pd) and platinum (Pt) electrocatalysts using a phase transfer method. This strategy involves acidic dissolution of deactivated precious metal (Pd/Pt) electrocatalysts from their loading substrates, mixing with an ethanolic solution of dodecylamine (DDA), subsequent extraction of metal ions into a non-polar organic phase, and final reduction by sodium borohydride to reproduce high-performance electrocatalysts towards typical electrochemical reactions, e.g. , oxygen reduction reaction (ORR) and ethanol oxidation reaction (EOR). In specific, the transfer efficiencies are up to 98% and the final recovery rate is over 85% for Pd and Pt electrocatalysts in each cycle. This approach symbolizes a facile and efficient way to recover precious metals, which might be applied to recycling a wide range of metals in various realms after appropriate modifications.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Xiaoyan Pei,Jiang Liu,Weihao Rao,Xiantao Ma,Zhiyong Li
Carbon dots (CDs) have attracted great attention in recent years owing to their potential applications in such as photocatalysts, organic synthesis, and bioimaging. However, it is always difficult for the separation and recycling of carbon dots from homogeneous reaction systems, which may limit their application in catalysis. A stimuli-responsive phase transfer of CDs is promising to solve these problems. In this work, we developed a novel class of CO2-responsive carbon dots decorated with different molecular weight polyetheramines (PEAs) (Mn = 230, 400, 2000 g/mol, respectively) and investigated their phase transfer behavior. It was found that PEA230-CD were well able to reversibly transfer between water and organic solvents by alternative bubbling and removal of CO2, the phase transfer efficiency of PEA400-CD was about 40%, and PEA2000-CD cannot transfer. The mechanism of the CO2-switched phase transfer involves the reversible reaction of PEA-functionalized CDs with CO2 and reversible formation of hydrophilic bicarbonates salts. As an example of applications, the phase transfer strategy was successfully applied in a Henry reaction by using the CDs as catalysts for efficient homogeneous catalysis, heterogeneous separation, and recycling of the CDs.
研究领域:
材料科学
·
化学工程
·
催化技术
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Zhiyu Zhao,Xiaolong Zhou,Qingfen Meng,Pengrui Zhang,Fei Shao,Xiao Li,Huangda Li,Lianjing Mao,Tianyu Zheng,Yan Jing,Yongzhong Jia,Shuxuan Wang,Jinhe Sun
High abundance 6Li and 7Li are essential materials for the nuclear industry. In this article, the lithium isotope separation effect and lithium-ion transport of a “lithium salt aqueous solution (anolyte)|crown ethers–ionic liquid organic solution|ammonium chloride aqueous solution (catholyte)” electromigration system with B12C4, B15C5 and B18C6 as phase transfer catalysts were investigated systematically. The results show that separation factors can reach 1.028 (B12C4), 1.024 (B15C5) and 1.011 (B18C6), respectively, when LiCl solution is used as the anolyte. The separation effect mainly originated from interfaces between anolytes and organic solutions, and was less affected by an electric field. The separation effect between organic solution and catholytes was greatly affected by the electric field for B12C4 and B15C5 systems, which converted from 7Li-enrichment to 6Li-enrichment with increased voltage. For the B18C6 system it was less affected. Furthermore, lithium ion transport in B12C4, B15C5 and B18C6 systems was greatly promoted by the electric field, with the Li+ concentration in catholytes of B12C4, B15C5 and B18C6 systems increased from 0.088 mg L−1, 0.286 mg L−1 and 0.778 mg L−1 to 8.321 mg L−1, 7.422 mg L−1 and 4.631 mg L−1 respectively as the voltage increased from 2 V to 16 V. The B12C4 system has been confirmed as the optimal solution considering both the Li+ transport and isotope separation effect.
研究领域:
核化学
·
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ChemElectroChem
·
2016
·Vol. 3
·期 11
·1781-1786
·
IF 3.506
Xiao Huang,Yaofang Xuan,Lisiqi Xie,Bin Su
Graphical Phase-transfer catalysis : Fe III meso -tetra-(4- N -methyl-pyridyl) porphine (Fe III TMPyP) is found to catalyze oxygen reduction at the liquid/liquid interface. Based on the size-selective ion-transfer voltammetry at the nanoscopic liquid/liquid interface, the reaction is rationalized to proceed through the phase-transfer catalysis mechanism. We report an investigation of the oxygen reduction reaction (ORR) catalyzed by Fe III meso -tetra-(4- N -methyl-pyridyl) porphine (Fe III TMPyP) at the polarized water/1,2-dichloroethane (DCE) interface. Fe III TMPyP is a water soluble pentavalent cation, which has a standard Galvani transfer potential of +0.19 V at the water/DCE interface. By four-electrode cyclic voltammetry and shake-flask biphasic reactions controlled by chemical polarization at the macroscale water/DCE interface, we demonstrated that Fe III TMPyP can catalyze the reduction of O 2 by electron donors (e.g., ferrocene and 1,1′-dimethylferrocene). Further, based on voltammetry at the free-standing silica nanochannel membrane (SNM) supported nano-ITIES (interface between two immiscible electrolyte solutions) array where the transfer of Fe III TMPyP is physically blocked owing to the size-exclusion effect, we proved that the overall reaction proceeds through a phase-transfer catalysis (PTC) process, namely the heterogeneous ion transfer of Fe III TMPyP from water to DCE followed by the homogeneous catalyzed ORR in DCE.
研究领域:
化学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2015
·Vol. 15
·期 3
·2305-2311
·
IF 1.556
Du Yingying,Yang Ping,Zhu Yuanna,Zhang Qiang
Monodispersed CdTe
x
Se1-x
and CdSe cores were synthesized via organic methods. The asprepared cores were coated with a Cd
y
Zn1-y
S shell by an epitaxial growth. Compared with the cores, an obvious red shift was observed
in both the absorption and photoluminescence (PL) spectra of core–shell quantum dots (QDs) and the PL efficiency was improved. The CdSe-based core–shell QDs were transferred from oil to water phase by the encapsulation of amphiphilic polymers. The ligands of QDs, namely hexadecylamine
(HDA) and oleic acid (OA), dramatically influenced the process of phase transfer. The process of phase transfer of HDA-coated CdTe
x
Se1-x
/Cd
y
Zn1-y
S core–shell QDs was failed, however, the OA-coated CdSe/Cd
y
Zn1-y
S
core–shell QDs can be successfully transferred from oil to water phase. This is ascribed that the surface ligand HDA falls from CdTe
x
Se1-x
/Cd
y
Zn1-y
S core–shell QDs during the process of phase transfer,
leading to non-interaction between QDs and amphiphilic polymers. The effect of molecular weight of the poly(styrene-co-maleic anhydride) (PSMA) on the phase transfer was also investigated. For the QDs with the same size, the PSMA with high molecular weight exhibit a shorter time in the process
of phase transfer compared with light molecular weight. Furthermore, the size of the QDs also affects the process of the phase transfer from oil to water phase. The smaller of the QDs, the shorter of the phase transfer time.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
Polymers
·
2022
·Vol. 14
·期 6
·1234
·
IF 4.967
Shuang Liu,Xin-Yao Quan,Hao-Ran Wang,Shuangquan Liao,Ming-Chao Luo
Zinc oxide (ZnO), which is toxic to aquatic organisms, is widely used as an activator in the rubber industry. The reduction of ZnO content is one of the efficient ways to tackle ecological environment impacts induced by ZnO. However, the incompatibility between Zn2+and organic matrix inhibits the solubility and activity of Zn2+in the organic matrix, causing the heavy use of ZnO. This work develops a phase transfer agent with Zn2+-philic structure and oleophilic structure to increase the solubility of Zn2+in the organic matrix. The phase transfer agent and Zn2+form coordination interactions, while the hydrophobic chains of phase transfer agent and organic matrix form hydrophobic interactions. The above two interactions improve the solubility and activity of Zn2+in the organic matrix, contributing to the formation of crosslinking network. Through the phase transfer agent strategy, we obtain the mechanically robust elastomers, and the samples with low ZnO content still maintain the superior properties. This work provides an efficient way to reduce ZnO content without sacrificing the performance of elastomers.Keywords:elastomers;phase transfer agent;crosslinking process;ZnO content;mechanical properties
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2018
·
IF 1.712
Yaling Luo,Changjun Liu,Hairong Yue,Siyang Tang,Yingming Zhu,Bin Liang
The selective oxidation of cyclopentene by aqueous H 2 O 2 using H 3 PW 12 O 40 and tetrabutyl ammonium bromide (TBAB) as a phase transfer catalyst has been investigated. The results show that the presence of TBAB significantly improved the oxidation selectivity of cyclopentene. The effects of the reaction conditions on the conversion of cyclopentene were investigated in detail. The optimal reaction conditions are as follows: the H 3 PW 12 O 40 to TBAB molar ratio, 1:1–1:3; H 3 PW 12 O 40 to cyclopentene molar ratio, 0.54:100–0.64:100; and molar ratio of H 2 O 2 to cyclopentene, 1.6:1. The conversion reached to 59.8% in 4 h at 35.0 °C, while the selectivity of glutaraldehyde was 38.0% and the selectivity of 1,2-cyclopentanediol was 55.6%. In addition, a route for oxidation of cyclopentene by aqueous H 2 O 2 using a heteropoly acid and quaternary ammonium salt as a phase transfer catalyst was proposed.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 35
·e202301065
·
IF 2.1
Min Zhang,Tian-Song Deng,Zhiqun Cheng
Graphical The transfer of gold nanorods (GNRs) to non-polar solvents enhances their self-assembly, biocompatibility, and surface-enhanced Raman scattering (SERS) abilities. However, the strong attachment of CTAB to the GNRs hinders their combination with other substances. Using ethanol as a ′catalyst′ lowers CTAB′s critical micelle concentration, facilitating its efficient combination with selected organosilanes, and the phase transfer process has been studied. The modified GNRs effectively self-assemble at the air-water interface. The plasmonic coupling between particles enhances the SERS activity, which is analyzed using varying concentrations of R6G. Transferring gold nanorods (GNRs) from an aqueous solution to a non-polar solvent enhances self-assembly, promotes biocompatibility, and boosts surface-enhanced Raman scattering (SERS). However, the strong attachment ability of toxic hexadecyltrimethylammonium bromide (CTAB) to GNRs presents a significant challenge in the fall of CTAB and combining with other substances for self-assembly and SERS applications. We propose a solution that employs ethanol as a ‘catalyst’ to lower the critical micelle concentration (CMC) of CTAB and efficiently combine it with the organosilanes formed by the hydrolysis of mercaptopropyltrimethoxysilane (MPS) and octadecyltrimethoxysilane (ODS). The samples were characterized by UV-vis-NIR spectroscopy, transmission electron microscopy (TEM), and energy disperse spectroscopy (EDS) mapping. A detailed interpretation of the phase transfer processes was provided. The modified particles were effectively dispersed in toluene and formed thin films at the air-water interface through self-assembly, which was confirmed by scanning electron microscopy (SEM) and optical microscopy. These films can serve as a platform for SERS.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2019
·Vol. 2019
·期 33
·3734-3739
·
IF 2.578
Jie Hu,Mu Li,Kun Chen,Panchao Yin
Graphical A phase transfer approach to controllably assemble core-shell nanoparticles through two different sized CdSe QDs and tri-lacunary Keggin-type POMs functionalized with thiol groups. A co-assembly protocol of quantum dots (QDs)-polyoxometalates (POMs) hybrids is developed using Keggin-type POMs as surface capping ligands. Phase transfer strategy is used to prepare POM-QDs nanocomposites. These newly developed hybrid materials have been explored for their optical properties and aggregation behavior in solutions. UV/Vis and FT-IR are used to reveal the optical properties of POM-QDs. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) are applied to characterize the co-assembled core-shell structures of POM-QDs complexes under different reaction conditions. A general trend to be noted is that the average photoluminescence (PL) lifetime of QDs decreases after phase transfer. The lifetime attenuation is caused by the surface property change of newly obtained POM-QDs complexes, which is resulted from the changed band edge recombination and shallow trap assisted recombination.
研究领域:
材料科学
·
纳米技术
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2016
·Vol. 46
·期 11
·1147-1155
·
IF 2.223
Jin Biyao,Zhang Yanyu,Zhao Lianhua
Abstract PdAu 3:1/C-1 and PdAu 3:1/C-2 nanoparticles were prepared in methylene chloride and water, respectively. The syntheses featured the use of tetrabutylammonium hydroxide as a phase-transfer agent and stabilizer. Electrochemical characterization showed that compared with PdAu 3:1/C-2, PdAu 3:1/C-1 had superior ethanol oxidation reaction (EOR) activity in alkaline media. The results of X-ray powder diffraction indicated that PdAu 3:1/C-1 was an alloy, whereas PdAu 3:1/C-2 was a heterogeneous mixture of the two metals. Moreover, transmission electron microscope analyses revealed that the PdAu 3:1/C-1 nanoparticles dispersed homogeneously on the carbon carrier without evident aggregation. Further, the X-ray photoelectron spectroscopy results demonstrated that the hydroxyl content was higher on the surface of PdAu 3:1/C-1 than that of PdAu 3:1/C-2. The increase of adsorptive hydroxyl on the surface of PdAu 3:1/C-1 could facilitate the adsorption and oxidation of CO on the catalyst surface, thus improving EOR activity and catalyst stability. Graphical Abstract
研究领域:
化学
·
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2023
·
IF 6.2
Qiang Tang,Qing-Yun Wu,Lin Gu
Graphene oxide (GO) nanocomposite lubricants have been verified with excellent anti−wear and anti−friction properties. However, the rapid transfer of hydrophilic GO nanosheets into hydrophobic lubricants still faces great challenges. In this work, a series of nanocomposite lubricants were successfully fabricated by a simple phase transfer process without complex chemical modification. With the assistance of ethanol and oleylamine, the GO nanosheets initially dispersed in the water phase could be quickly transferred to the mineral oil within 20 s after hand-shaking the immiscible two−phase system. Moreover, the phase−transferred GO nanosheets were greatly stable in the mineral oil for at least seven days. The tribological properties of the GO nanocomposite lubricants had been studied by a macroscopic ball−on−disk friction test. The tribological behavior of the obtained nanocomposite lubricants showed that when 0.1 mg/mL GO was dispersed into mineral oil, the minimum average friction coefficient was 0.140, which was 72% lower than that of mineral oil. The universality of the phase transfer process was verified by the reduced GO nanosheets. This physical phase transfer method must be simple, effective, and environment−friendly to prepare nanocomposite lubricants.
研究领域:
材料科学
·
化学工程
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Chuxin Qi,Lifang Chen,Zhiwen Qi
The heterogeneous liquid–liquid O-glycosidation is a crucial step in pharmaceutical synthesis. Herein, a theoretical methodology based on COSMO-RS, quantum chemical calculations combined with Transformer-CNN model was used to screen ionic liquids (ILs) as phase transfer catalysts (PTCs) to intensify O-glycosidation between 4-nitrophenol and 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl bromide. The anions of ILs were screened by the evaluation of ILs hydrophilicity via infinite dilution selectivity of ILs and the molecular descriptor HB_acc3 of the anion using COSMO-RS, a predictive model for thermodynamic properties. Additionally, the binding energy between the phenoxide anion and IL cation was used to assess reaction extent in the aqueous phase through quantum chemical calculation. The cations of ILs were evaluated by the infinite dilution selectivity of the combination between phenoxide anion and IL cations, and physical properties including viscosity and melting point were also predicted using an advanced Transformer-CNN model. The screened IL 1-octyl-3-methylimidazolium acetate and 1-hexyl-3-methylimidazolium acetate were demonstrated its superior catalytic activity for the aromatic O-glycosidation of not only 4-nitrophenol, but also various phenols and thiophenols. Moreover, the presence of PTCs enhances the likelihood of the reactant migrating into another phase. This behavior is validated by COSMO-RS calculated liquid–liquid equilibrium (LLE) and interaction energy analysis. The method provides great potential for screening and designing ILs as phase transfer catalysts for heterogeneous liquid–liquid reactions.
研究领域:
有机化学
·
药物合成
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）