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519 results on '"Zhai, Quan‐Guo"'

53. De‐Linker‐Enabled Exceptional Volumetric Acetylene Storage Capacity and Benchmark C2H2/C2H4 and C2H2/CO2 Separations in Metal–Organic Frameworks.

Author

Wang, Jia‐Wen, Fan, Shu‐Cong, Li, Hai‐Peng, Bu, Xianhui, Xue, Ying‐Ying, and Zhai, Quan‐Guo

Subjects
METAL-organic frameworks, ACETYLENE, STORAGE, ZEOLITES, SORBENTS
Abstract

An ideal adsorbent for separation requires optimizing both storage capacity and selectivity, but maximizing both or achieving a desired balance remain challenging. Herein, a de‐linker strategy is proposed to address this issue for metal–organic frameworks (MOFs). Broadly speaking, the de‐linker idea targets a class of materials that may be viewed as being intermediate between zeolites and MOFs. Its feasibility is shown here by a series of ultra‐microporous MOFs (SNNU‐98‐M, M=Mn, Co, Ni, Zn). SNNU‐98 exhibit high volumetric C2H2 uptake capacity under low and ambient pressures (175.3 cm3 cm−3 @ 0.1 bar, 222.9 cm3 cm−3 @ 1 bar, 298 K), as well as extraordinary selectivity (2405.7 for C2H2/C2H4, 22.7 for C2H2/CO2). Remarkably, SNNU‐98‐Mn can efficiently separate C2H2 from C2H2/CO2 and C2H2/C2H4 mixtures with a benchmark C2H2/C2H4 (1/99) breakthrough time of 2325 min g−1, and produce 99.9999 % C2H4 with a productivity up to 64.6 mmol g−1, surpassing values of reported MOF adsorbents. [ABSTRACT FROM AUTHOR]

Published
2023
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62. Controllable inverse C2H2/CO2 separation in ultra-stable Zn-organic frameworks for efficient removal of trace CO2 from acetylene.

Author

Yu, Jia, Zhang, Jing, Zhang, Peng, Wang, Ying, Li, Shu-Ni, and Zhai, Quan-Guo

Abstract

It is of great challenge to produce highly pure C2H2 from the CO2/C2H2 mixture because of their similar physical properties. Metal–organic frameworks (MOFs) have shown great potential in purifying C2H2 by virtue of their versatile pore environment with excellent tunability. However, the rational exploration of ideal MOF adsorbents with CO2-preferred CO2/C2H2 separation performance (also called inverse C2H2/CO2 separation) is extremely difficult. In this work, we demonstrate a new Zn-MOF family (SNNU-334–336) with special CO2-preferred CO2/C2H2 separation performance, which can be rationally controlled by functional groups as well as temperature. Notably, SNNU-334–336 MOFs show extremely high stability, and SNNU-336 can maintain a stable structure even after 7 days in boiling water and 30 days in air, which is unprecedented for all Zn-based MOF materials. Different to common MOF adsorbents, the adsorption isotherms of SNNU-334–336 MOFs for C2H2 and CO2 under the same temperature all have an intersection point (we called the inverse point), which gradually moves to the high-pressure region with the increase of temperature and changes with the pore environment variation. So, SNNU-334–336 MOFs can be rationally controlled from C2H2-selective to CO2-selective CO2/C2H2 adsorption separation adsorbents. IAST selectivity calculation indicates that a very high CO2 over C2H2 selectivity (3595.4) can be achieved, which nearly surpasses those of all reported MOFs with CO2-preferred CO2/C2H2 separation performance. Fixed-bed column breakthrough experiments further prove that SNNU-334–336 MOFs all have controllable inverse CO2/C2H2 separation ability and can produce C2H2 with extra-high purity (>99.9%) from the CO2/C2H2 (1/99) mixture. [ABSTRACT FROM AUTHOR]

Published
2022
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78. Precise Introduction of Single Vanadium Site into Indium–Organic Framework for CO2Capture and Photocatalytic Fixation

Author

Fan, Shu-Cong, Chen, Shuang-Qiu, Wang, Jia-Wen, Li, Yong-Peng, Zhang, Peng, Wang, Ying, Yuan, Wenyu, and Zhai, Quan-Guo

Abstract

The capture and fixation of CO2under mild conditions is a cost-effective route to reduce greenhouse gases, but it is challenging because of the low conversion and selectivity issues. Metal–organic frameworks (MOFs) are promising in the fields of adsorption and catalysis because of their structural tunability and variability. However, the precise structural design of MOFs is always pursued and elusive. In this work, a metal-mixed MOF (SNNU-97-InV) was designed by precisely introducing single vanadium site into the isostructural In-MOF (SNNU-97-In). The single V sites clearly change the interactions between the MOF framework and CO2molecules, leading to a 71.3% improvement in the CO2adsorption capacity. At the same time, the enhanced light absorption enables SNNU-97-InV to efficiently convert CO2into cyclic carbonates (CCs) with epoxides under illumination. Controlled experiments showed that the promoted performance of SNNU-97-InV may be that the V═O site can more easily combine with CO2and convert them into an intermediate state under illumination, and the possible mechanism was thus speculated.

Published
2022
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90. Enhancement of the fluorescence properties via introducing the tetraphenylethylene chromophores into a novel Mn–organic framework with a rare [Mn4(μ3-OH)2] cluster.

Author

Zhang, Jian-Wei, Li, Hui, Li, Jie-Qiong, Chen, Ya, Qu, Peng, and Zhai, Quan-Guo

Subjects
TETRAPHENYLETHYLENE, CHROMOPHORES, FLUORESCENCE, ETHYLENE, THERMOMETERS
Abstract

By employing a tetraphenylethylene (TPE)-based tetracarboxylate linker, tetrakis(4-carboxyphenyl)ethylene (H4TCPE), we herein constructed a novel luminescent Mn-MOF based on a rare [Mn4(μ3-OH)2] cluster (SQNU-55). Interestingly, the TPE-based SQNU-55 not only provides a good material for the blue LED device, but also has a better luminescent molecular thermometer for low-temperature detection. [ABSTRACT FROM AUTHOR]

Published
2021
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99. Equilibrium phase behavior of ethylene glycol/glycerin+RbNO3/CsNO3+H2O at 288.15 and 298.15 K

Author

Zhang Huiying, Zhai Quan-Guo, Zhu Weiwei, Li Shuni, Hu Mancheng, and Jiang Yu-cheng

Subjects
chemistry.chemical_classification, Aqueous solution, Chemistry, Inorganic chemistry, Salt (chemistry), chemistry.chemical_element, General Chemistry, chemistry.chemical_compound, Caesium, Rubidium nitrate, Solubility, Ternary operation, Mass fraction, Ethylene glycol
Abstract

The solubilities, densities and refractive indices for the four ternary systems ethylene glycol/glycerin+RbNO3/CsNO3+H2O were measured with mass fractions of ethylene glycol or glycerin in a range of 0 to 1.0 at 288.15 and 298.15 K. In all the cases, the presence of either ethylene glycol or glycerin significantly reduces the solubilities of the rubidium nitrate and cesium nitrate in aqueous solution, but the refractive indices increase with the increase of mass fraction of either ethylene glycol or glycerin. The density, refractive index and solubility of the saturated ternary systems were correlated with each other via polynomial equations. In addition, the refractive indices and densities of unsaturated solutions were also determined for the four ternary systems with different salt concentrations, which were correlated with the salt concentration and proportion of ethylene glycol or glycerin in the solution.

Published
2014

100. Modulation of p-Block Electron Orbits in Metal–Organic Frameworks for CO2Capture and Electrochemical Reduction

Author

Shao, Li-Yang, Wang, Shuo, Li, Shu-Ni, Meng, Jie, Yue, Jiao-Na, Yuan, Wen-Yu, Wang, Ying, and Zhai, Quan-Guo

Abstract

Developing catalysts with excellent CO2capture capability and electrochemical CO2reduction reaction (CO2RR) at a wide potential range simultaneously is significant but remains a formidable challenge. Here, two novel InMg defective trinuclear cluster-based MOFs (SNNU-41 and SNNU-42) with abundant p-block unsaturated coordinated sites were reported and exhibited good CO2capture and CO2RR performance simultaneously. Due to the suitable micropores, SNNU-41 showed higher CO2capture ability at different adsorption pressure conditions. On account of the rigid framework and the closer pband center to Fermi level, SNNU-42 accelerated the conversion of CO2molecule to C1 efficiency. Notably, via adjusting the ratio of p-block metal (In) in the SNNU-42 framework, the performance of the CO2RR was promoted drastically. SNNU-42 with the InMg (1:1.8) mixed cluster delivered an excellent Faradaic efficiency of 91.3% for C1 products and high selectivity of 72.0% for HCOOH at −2.5 V (vs Ag/Ag+) with a total current density of 77.2 mA cm–2. This work provides a possibility for efficient CO2capture and CO2RR electrocatalysts through the modulation of electronic structures and composition in MOFs.

Published
2024
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