JOM
·
2018
·Vol. 70
·期 12
·2837-2845
·
IF 2.145
Zhang Weiguang,Zhang Ting-An,Lv Guozhi,Zhou Weihua,Cao Xuejiao,Zhu Hangyu
The solvent extraction and separation process of Sc(III) and Fe(III) from a strongly acidic and highly concentrated ferric solution using mixtures of di(2-ethylhexyl) phosphate (D2EHPA) and tri-n-butyl phosphate (TBP) in sulfonated kerosene was studied. The effects of various parameters, including D2EHPA concentration, dosage of TBP, and phase ratio, were investigated for the extraction process. The results indicated that the extraction rate of Sc(III) was 99.72% with 1.09% Fe(III) co-extracted after two stages of counter-current extraction under optimal conditions. Moreover, saturation capacity and slope analysis were used to determine the reaction mechanism. Sc(III) is extracted in the form of HSc(SO 4 ) 2 ·4HL. Further separation of Sc(III) and Fe(III) was realized in a scrubbing and stripping process. First, 98.67% of the co-extracted iron in the loaded organic phase was scrubbed with a dilute HCl solution by a three-stage counter-current scrubbing. Then, 85.00% of Sc(III) can be stripped efficiently with a 2-mol/L NaOH solution saturated in 1-mol/L NaCl by three-stage cross-current stripping.
研究领域:
化学工程
·
分析化学
·
环境科学
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产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2026
·Vol. 83
·期 11
·626
·
IF 4.2
Liu Xiaoqi,Zhang Renyun,Chen Ting,Xiang Luodan,Wang Jing,Lv Guozhi,Liu Yan,Zhang Ting’an
Chitosan modified with polyethylene glycol-200 and crosslinked with glutaraldehyde (MCS) was synthesized for the recovery of Sc(III) ions from aqueous solutions. The prepared adsorbents were characterized by FT-IR, TGA, BET, XRD, XRF, and SEM. The effects of solution pH, adsorbent dosage, contact time, initial concentration, and temperature on the adsorption performance were systematically investigated. The characterization results confirmed the successful fabrication of MCS, and the PEG-200-assisted pore-forming strategy improved the accessible pore structure and Sc(III) adsorption performance of MCS relative to glutaraldehyde-crosslinked chitosan (GCS). A working pH of 5, an adsorbent dosage of 50 mg, a contact time of 100 min, and a temperature of 30 °C were selected for the subsequent adsorption experiments. The adsorption kinetics, isotherms, and thermodynamics of Sc(III) onto MCS were further investigated. The adsorption data were best described by the pseudo-second-order kinetic and Langmuir isotherm models, and the Langmuir model predicted a maximum monolayer adsorption capacity of 55.28 mg·g −1 at 30 °C. The adsorption of Sc(III) was mainly associated with coordination interactions, electrostatic attraction, and hydrogen bonding involving the N/O-containing functional groups of MCS. The synergistic combination of PEG-200-assisted pore formation and GA crosslinking helped balance acid stability and pore accessibility, indicating that MCS has potential as an adsorbent for Sc(III) recovery from acidic aqueous media.
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DOI
高影响因子
DALTON TRANSACTIONS
·
2015
·Vol. 44
·期 40
·17508-17515
·
IF 4.197
Shuhao Qin,Lei Dong,Zhuqi Chen,Sicheng Zhang,Guochuan Yin
In Wacker oxidation and inspired Pd(II)/Cu(II)-catalyzed C–H activations, copper(II) is believed to serve in re-oxidizing of Pd(0) in the catalytic cycle. Herein we report that non-redox metal ions like Sc(III) can promote Wacker-type oxidations even better than Cu(II); both Sc(III) and Cu(II) can greatly promote Pd(II)-catalyzed olefin isomerization in which the redox properties of Cu(II) are not essential, indicating that the Lewis acid properties of Cu(II) can play a significant role in Pd(II)-catalyzed C–H activations in addition to its redox properties. Characterization of catalysts using UV-Vis and NMR indicated that adding Sc(OTf)3 to the acetonitrile solution of Pd(OAc)2 generates a new Pd(II)/Sc(III) bimetallic complex having a diacetate bridge which serves as the key active species for Wacker-type oxidation and olefin isomerization. Linkage of trivalent Sc(III) to the Pd(II) species makes it more electron-deficient, thus facilitating the coordination of olefin to the Pd(II) cation. Due to the improved electron transfer from olefin to the Pd(II) cation, it benefits the nucleophilic attack of water on the olefinic double bond, leading to efficient olefin oxidation. The presence of excess Sc(III) prevents the palladium(0) black formation, which has been rationalized by the formation of the Sc(III)⋯H–Pd(II) intermediate. This intermediate inhibits the reductive elimination of the H–Pd(II) bond, and facilitates the oxygen insertion to form the HOO–Pd(II) intermediate, and thus avoids the formation of the inactive palladium(0) black. The Lewis acid promoted Wacker-type oxidation and olefin isomerization demonstrated here may open up a new opportunity in catalyst design for versatile C–H activations.
研究领域:
化学
·
催化科学
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Yi Zhang,Yu Deng,Weidong Guo,Donghao Liu,Yigang Ding
Developing the efficient ionic liquid (IL)-based extractants for the solvent extraction of the rare earth elements (REEs) is crucial but still facing challenges. In this study, two carboxylic acid-functionalized upper critical solution temperature (UCST)-type ILs, N-carboxymethylpyridinium bis(trifluoromethylsulfonyl)imide ([HbetPy][Tf2N]) and N-carboxymethyl-N-methylmorpholinium bis(trifluoromethylsulfonyl)imide ([HbetMor][Tf2N]), are successfully synthesized and characterized. The extraction and separation performance toward scandium [denoted as Sc(III)] in nitrate medium aqueous solution have been carefully investigated in the homogeneous liquid–liquid extraction system under different conditions (e.g., equilibrium time, initial acidity, salting-out agent concentration, and REE concentration). The results reveal that the enhanced extractabilities of Sc(III) can be observed in homogeneous extraction compared to the biphasic system owing to the improved metal ion transfer and accelerated extraction kinetics. Meanwhile, [HbetPy][Tf2N] and [HbetMor][Tf2N] both illustrate high selectivity for Sc(III) separated from another five REEs (including La, Nd, Eu, Ho, and Yb), with the separation factors of 749 and 499 for Sc(III)/Yb(III), respectively. Moreover, the mechanism investigation indicates the formation of the Sc(III) complex via a proton exchange, evolved from the slope analysis and Fourier-transform infrared results. This study provides a prototype for the construction of the homogeneous liquid–liquid extraction system via the novel UCST-type ILs for highly efficient REE extraction and supplies the future application for the recovery of REEs from wastes.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
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