INORGANIC CHEMISTRY COMMUNICATIONS
·
2021
·
IF 2.495
Dan Liang,Yunfeng Hu,Qiang Bao,Jian Zhang,Jiawei Feng,Penglai Sun,Yutong Ma,Hongsheng Zhang
Rho zeolite was successfully synthesized by hydrothermal synthesis adopting 18-crown-6 as template, and the cations (H + , Na + , K + , Cs + , Cd 2+ and Pb 2+ ) of different radii were introduced into the framework of Rho by ion exchange. The samples were characterized by XRD, SEM-EDX, ICP and N 2 -BET. The adsorption behavior of CO 2 and CH 4 on cation-exchanged Rho was measured, and the adsorption isotherm was fitted by Langmuir equation to study the adsorption performance of these zeolites. The adsorption results show that the pore size of Rho is not solely dependent on the cation radius, the different positions of the cations are also more crucial in pore size adjustment. In all researched Rho, the introduction of Cd 2+ and Pb 2+ can more significantly reduce the pore size, and completely restrict the entry of CH 4 , thereby further improving the CO 2 /CH 4 selectivity. Therein, Cd-Rho has the best adsorption performance, with considerable CO 2 adsorption capacity, and extremely high CO 2 /CH 4 selectivity and CO 2 working capacity, which provides a new clue for the development of adsorbents for CO 2 and CH 4 separation in PSA process.
研究领域:
材料科学
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环境工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Ya Li,Ran Bi,Yanlei Su,Yafei Li,Chao Yang,Xinda You,Jianliang Shen,Jinqiu Yuan,Runnan Zhang,Zhongyi Jiang
Nanofiltration (NF) is a promising technology for fast molecular and ionic separation. Pore engineering is a critical but challenging strategy to fabricate NF membranes with high permeability and precise sieving ability. Herein, we proposed a post-modification approach to regulate the pore size of graphene quantum dots (GQDs) composite NF membranes by using a small molecule p-aminobenzoic acid (PABA) as a modifier. First, GQDs were used as the aqueous phase monomer of interfacial polymerization to react with trimesoyl chloride within the pores of the porous substrate, thereby fabricating large-pore-size GQDs composite NF membranes. After that, the self-polymerization of PABA within the pores of GQDs NF membranes would form nanoaggregates with different sizes, thus finely tuning the pore size of the as-prepared membrane. The PABA-modified membranes exhibited a range of pore sizes from 2.18 to 1.50 nm with the increased concentration of PABA. Specifically, the optimal PABA-modified membrane showed high water permeance of 128.1 L m −2 h −1 bar −1 and complete interception of 1000 Da-higher dye molecules, with desirable dye/salt selectivity factors of 877.0 and 175.4 for Alcian Blue/Na 2 SO 4 and Evans Blue/Na 2 SO 4 separation systems, respectively. Moreover, the membranes exhibited outstanding physicochemical stability. This study provides a facile method for pore size regulation of NF membranes.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 33
·21574-21581
·
IF 4.036
Junfeng Zhu,Xiaorong Meng,Wen Liu,Yabing Qi,Siyi Jin,Shanshan Huo
We present an efficient and easy synthesis method for incorporating organocatalytic moieties into Zr-metal organic frameworks (Zr-MOFs). The catalytic activity and selectivity of the new chiral catalysts were improved by adjusting the aperture of the MOF cavities. The hole size of the Zr-MOF was modulated by adding acid and replacing bridge ligands during synthesis. The difunctional chiral units of amino acid–thiourea are anchored onto the Zr-MOF by a mild synthesis method from an isothiocyanate intermediate which could effectively avoid the racemization of chiral moieties in the synthesis process. By means of specific surface area measurement (BET), scanning electron microscopy (SEM) and powder X-ray Diffraction (PXRD), it was confirmed that Zr-MOFs with different pore sizes were synthesized without breaking the basic octahedral structure of the MOF. Finally, good yields (up to 83%) and ee values (up to 73%) were achieved with the new heterogeneous catalysts in 48 hours for the aldol reaction of 4-nitrobenzaldehyde with acetone. By contrast, using the catalyst support without modulating the synthesis, the yield (30%) and the ee-value (26%) were both low. Experiments have confirmed the important influence on the reaction selectivity of providing a suitable reaction environment by controlling the aperture of MOF cavities.
研究领域:
材料化学
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有机合成
·
催化化学
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DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2020
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IF 4.089
Zhaotong Yan,Youjin Gong,Chu-Ting Yang,Xiaonan Wu,Boyu Liu,Qiang Liu,Shunshun Xiong,Shuming Peng
The design and construction of radioactive stable metal–organic frameworks (MOFs) are highly desirable for noble gases (Xe and Kr) separation from off-gas steams during used nuclear fuel reprocessing under radiation environments. Al-based MOFs are promising for realistic applications of Xe/Kr separation due to their high hydrothermal and chemical stability and comparatively easy and massive preparation by nonpoisonous, abundant, and cheap metal. Herein, we report on two isoreticular microporous Al-MOFs Al-Fum (Al-fumarate, Basolite A520) and Al-Fum-Me (Al-methyl-fumarate) with high radioactive stability for Xe/Kr separation. Appending methyl groups on the framework provides an effective approach to reduce and fine-tune the pore size of Al-Fum-Me to match well with the Xe atom and remarkably improve the framework-Xe affinity. Al-Fum-Me exhibits significantly enhanced Xe/Kr separation performance compared to Al-Fum, demonstrated by adsorption isotherms and breakthrough experiments. Gamma-ray irradiation experiments also identified the high radioactive stability of Al-Fum-Me, suggesting its great potential for practical application on Xe/Kr separation.
研究领域:
材料科学
·
核能工程
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）