DESALINATION
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2022
·
IF 11.211
Xiumin Zhang,Yongping Dong,Qingyi Wang,Hang Yu,Congjie Gao,Lixin Xue
Structures and NF performance of TFC-Co and TFC membranes activated with 50 % alcohol solutions were studied. Methanol and glycol solution activation increased water flux 2–4 times without trading off salt rejection while glycerin solution activation increased water flux 3–4 times with reduced salt rejection and increased dye/salt retention selectivity . The Stokes radius of TFC-Co membrane changed from 0.77 nm to 0.66, 0.78 and 0.92 nm while the TFC membrane changed from 0.54 nm to 0.55, 0.65 and 0.70 nm after activation with methanol, glycol and glycerin solutions, respectively. Capillary pore filling models were developed from pure alcohol absorption experiments including the stages of initial pore filling, pore expansion, pore relaxation and pore adjustment, while most Stokes radius after 50 % solutions activation were found to be close to the relaxed pore radius values (r rx ) or half of the expanded pore radius values (r ex ) from pure alcohol absorption experiments.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Hongxu Tao,Haiqian Lian,Jingxian Hua,Shengui Ju,Yichang Pan
The MOF membrane has shown great promise for the gases or organic solvent mixtures separation. However, the implementation of MOF membranes remains challenged by defect formation during membrane fabrication. Herein, we reveal that the activation solvent plays a critical role in governing the degree of defect and separation performance in secondary-growth-derived ZIF-8 membranes. The isopropanol activation process exerts excellent membrane structure protection through a synergistic dual mechanism to limit the generation of ZIF-8 membrane defects during drying: (a) The isopropanol inhibits the ZIF-8 seed layer recrystallization and maintains its porous architecture to mitigate interfacial stress during drying through its elastic deformation. (b) The low surface tension of isopropanol minimizes the capillary force during solvent removal to reduce the risk of structural damage. While methanol activation and n-propanol activation have no such structure control. The optimized isopropanol-activated membrane achieves a C 3 H 6 /C 3 H 8 selectivity of 141 to show a 4.8-fold and a 4.4-fold compared to n-propanol- and methanol-activated membranes at room temperature and 1 bar. This study highlights low-surface-tension as an effective strategy for defect suppression in MOF membranes, advancing their potential for industrial hydrocarbon separations.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Meng-Meng Tang,Xiao-Gang Jin,Xin Tang,Miao Yu,Xiao-Hua Ma,Zhen-Liang Xu
Dye wastewater poses a severe danger to the environment and human health. The purification of dye wastewater is the focus and hotspot of most researchers. In this work, ethylene glycol (EG) was selected as an aqueous phase monomer to fabricate polyester membranes through an interfacial polymerization reaction. Then the polyester membrane was activated by ethanol aqueous solution. By adjusting the activation time and concentration of the ethanol, the network of the polyester membrane can be reshaped to endow the membrane with excellent performance. The activation mechanism was also explored here. Compared to the membrane without activation (PE-0%), the permeability of the optimized membrane (PE-40%) was increased by 8.3 times, and a high rejection was maintained (CR: 99.2%). Importantly, the PE-40% membrane also presented good acid and alkali resistance, chlorine resistance, and excellent antifouling performance. Our work provides an effective and feasible strategy for the development of high-performance polyester membranes.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2024
·Vol. 48
·期 47
·20061-20070
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IF 2.7
Jiabing Chen,Yibo Tang,Xiaojun Lu,Zijing Lu,Xingmao Jiang
The industrial production of methyl propionate synthesized via methoxycarbonyl esterification of ethylene achieved 100% atom economy. In this study, we synthesized ruthenium-loaded praseodymium–cerium oxide (Pr–CeO2) catalysts by precipitation impregnation and evaluated their performance in the methoxycarbonylation reaction of ethylene. The effect of Pr doping on the reaction results was analyzed by characterization and mechanistic studies. Pr doping increased the concentration of localized oxygen vacancies in the catalysts and thus modulated the catalytic effect of Lewis acid–base pairs. The increase of local oxygen vacancies significantly enhanced the activation and dissociation of CH3OH. At the same time, since the dissociation activation of the other two feedstock molecules, ethylene and CO, occurred at the Ru site, Pr doping facilitated the dispersion of Ru to a certain extent, thus increasing the dissociation activation of CO and ethylene, which, in combination with Pr doping, further increased the content of oxygen vacancies in the active site as methanol, resulting in a substantial enhancement of the dissociation activation of the feedstock molecules, which then increased the catalytic reaction rate through synergistic effects. The results provide a new perspective for the future study of methoxycarbonylation.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
ACS Catalysis
·
2023
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IF 12.9
Zhao Sun,Shufan Yu,Sam Toan,Rufat Abiev,Maohong Fan,Zhiqiang Sun
Steam reforming of methanol is a promising approach to achieving hydrogen storage, transportation, and in situ supply. However, this technology is restricted by its high CO selectivity and catalyst deactivation. In this study, CuCr2O4-based catalytic oxygen carriers are tailored for lattice oxygen participating in low-temperature methanol reforming. We found that the low-temperature activation of methanol originated from Cu–O–Cr structure intensification and highly activated lattice oxygen induction. Specifically, methanol can be activated at temperatures as low as 160 °C, on the one hand, attributed to the reinforcement of the Cu–O–Cr structure and, on the other hand, owing to the highly reactive lattice oxygen from the CuO4 tetrahedron in the CuCr2O4 spinel. Combined with XAS and Raman results, the formation of the Cu–O–Cr structure is demonstrated. The hydrogen production rate with an applied CuCr2O4-based catalytic oxygen carrier is 53.2% higher than the control group without Cu–O–Cr formulation. Satisfactory cyclic stability is retained after the 50th lattice oxygen induction and supplement cycle, ascribing to the Cu–O–Cr structure that strongly intensifies Cu–Cr2O3 interactions. DFT results reveal that the process of CH3OH → CH3O* is the rate-determining step. Compared to Cu(111) and Cr2O3(110), the tailored Cu(111)/Cr2O3(110) surface with a Cu–O–Cr structure exhibits the lowest potential barrier during this process, promoting low-temperature methanol reforming.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2023
·Vol. 69
·期 10
·e18158
·
IF 3.7
Han Han,Xue Ye,Jie Yao,Xinhua Gao,Jinghao Yu,Lisheng Guo,Jie Li
The application of heterogeneous catalysts in dimethyl carbonate (DMC) synthesis from methanol is hindered by low activation efficiency of methanol to methoxy intermediates (CH 3 O*), which is the key intermediate for DMC generation. Herein, a catalyst of alkali metal K anchored on the CuO/ZnO oxide is rationally designed for offering Lewis acid–base pairs as dual active centers to improve the activation efficiency of methanol. Characterizations of CO 2 -TPD, NH 3 -TPD, XPS, and DRIFTS revealed that the addition of Lewis base K observably boosted the dissociation of methanol and combined with Lewis acid CuO/ZnO oxide to adsorb the formed CH 3 O* stably, thus synergistically promoted the transesterification. Finally, the CuO/ZnO-9%K 2 O catalyst exhibited the optimal catalytic activity, achieving a high yield of 74.4% with an excellent selectivity of 98.9% for DMC at a low temperature of 90°C. The strategy of constructing Lewis acid–base pairs provides a reference for the design of heterogeneous catalysts.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2020
·
IF 7.888
Jian Zhang,Yazhe Zhang,Jieqiong Zhao,Zhe An,Yanru Zhu,Xin Shu,Hongyan Song,Xu Xiang,Xiaodan Ma,Jing He
Oxidative carbonylation has attracted broad interest from both academia and industry in recent years. Oxycarbonylation of ethanol to diethyl carbonate (DEC) has been of great challenge due to the difficulty in the simultaneous activation of ethanol and CO. This work reports a heterogeneous Cu-Pd pair catalysis for simultaneous activation of ethanol and CO, affording a selectivity of 85.4% to DEC and a space–time yield (STY) of up to 207 mg∙g −1 ∙h −1 . Well distributed Cu-Pd pair affords more Cu (I) sites, promoting CO activation and the followed insertion to adsorbed ethanol. Further increasing ratio of Cu (I) species via the pre-treatment of catalyst with CO and ethanol promotes simultaneously the activation of ethanol and CO, affording a STY of 325 mg∙g −1 ∙h −1 of DEC.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2019
·
IF 6.97
Wenwen Qiang,Xiang Liu,Teck-Peng Loh
The first example of a heterogeneous catalyst based on hydrotalcite-derived Mg–Al oxides supported iridium (Ir/MgxAlO) for activation of methanol in the synthesis of bis(indolyl)methanes (BIMs) is reported. In this clean and reusable iridium-based catalytic system, a variety of substituted indoles were selectively converted to their corresponding BIMs in moderate to good yields with high tolerance to reducible functional groups by using methanol as a bridging methylene (−CH2−) donor. The high catalytic activity and selectivity of the reaction benefit from the delicate cooperation of redox/acid–base surface sites on this artificially designed multifunctional Ir/MgxAlO catalyst. The overall simplicity, chemoselectivity and sustainability of the catalytic system make this approach a valuable and step-economical tool to construct C–C bond directly from methanol in the synthesis of more complex molecules.
研究领域:
化学
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催化材料科学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-15
·
IF 14.7
Liu Xixi,Huang Liang,Ma Yuandie,She Guoqiang,Zhou Peng,Zhu Liangfang,Zhang Zehui
A single-atom catalyst with generally regarded inert Zn–N 4 motifs derived from ZIF-8 is unexpectedly efficient for the activation of alcohols, enabling alcohol-mediated alkylation and transfer hydrogenation. C-alkylation of nitriles, ketones, alcohols, N -heterocycles, amides, keto acids, and esters, and N -alkylation of amines and amides all go smoothly with the developed method. Taking the α-alkylation of nitriles with alcohols as an example, the α-alkylation starts from the (1) nitrogen-doped carbon support catalyzed dehydrogenation of alcohols into aldehydes, which further condensed with nitriles to give vinyl nitriles, followed by (2) transfer hydrogenation of C=C bonds in vinyl nitriles on Zn–N 4 sites. The experimental results and DFT calculations reveal that the Lewis acidic Zn-N 4 sites promote step (2) by activating the alcohols. This is the first example of highly efficient single-atom catalysts for various organic transformations with biomass-derived alcohols as the alkylating reagents and hydrogen donors.
研究领域:
催化
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有机化学
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材料科学
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化学工程
✓ 已验证
DOI
PubMed
高影响因子
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