CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Renhui Ling,Mingxing Li,Xin Li,Laihuan Pei,Xiaoyan Luo,Congmin Wang
MOFs have high adsorption performance of ammonia (NH 3 ) because of its porosity and abundant coordination sites, especially MOFs containing carboxylic acid ligands have emerged as effect NH 3 adsorbents. But, it’s troublous for reversible ammonia adsorption for the strong metal-NH 3 coordination or the collapse of adsorbents. [MEDTA] 2- is a very stable and classic carboxylic acid-containing complex, but there was no relevant report. Therefore, this work carried out the design and synthesis of PVIm-R8-MEDTA based on the use of the coordination structure of [MEDTA] 2- and the stability of PILs’ skeleton. The characterization indicated the [MEDTA] 2- could be introduced into PILs successfully for the hydrogen bonding interactions with the imidazolium cation, and the obtained PVIm-R8-MEDTA presented enhanced NH 3 capacity (10.4–14.7 mmol/g) than their precursor PVIm-R8-Br (7.8 mmol/g). The mechanism of NH 3 adsorption was proposed by DFT calculation, spectroscopic method, and the calorimetric test, it indicated the NH 3 was fixed by imdazolium cation through hydrogen bonding and inserted into two of the carboxylate and metal bonds of [MEDTA] 2- . Because of the multi-meshing coordination of [EDTA] 4- and metal ions, the disconnected carboxylate ions could easily coordinate with metal ions again and repair the chelating structure of [MEDTA] 2- , which caused the ammonia easily be desorbed. In the process of gas adsorption, there was no bonding breakage of the skeleton of PILs, which helped the PVIm-R8-MEDTA be recovered under moisture and NH 3 atmosphere. Thanks for the designability of PILs, such as the cationic structure, structure and size of cross-linking agent, the choice of complex anion and so on, it provides a new design idea and theoretical basis for efficient and reversible ammonia adsorption materials.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 7
·2903
·
IF 3.4
Youye Ma,Kanghui Cai,Guojie Xu,Yueling Xie,Peng Huang,Jun Zeng,Ziming Zhu,Jie Luo,Huawen Hu,Kai Zhao,Min Chen,Kun Zheng
Ultrafine Polyvinyl alcohol (PVA) fibers have an outstanding potential in various applications, especially in absorbing fields. In this manuscript, an electrostatic-field-assisted centrifugal spinning system was designed to improve the production efficiency of ultrafine PVA fibers from PVA aqueous solution for NH3adsorption. It was established that the fiber production efficiency using this self-designed system could be about 1000 times higher over traditional electrospinning system. The produced PVA fibers establish high morphology homogeneity. The impact of processing variables of the constructed spinning system including rotation speed, needle size, liquid feeding rate, and voltage on fiber morphology and diameter was systematically investigated by SEM studies. To acquire homogeneous ultrafine PVA fiber membranes, the orthogonal experiment was also conducted to optimize the spinning process parameters. The impact weight of different studied parameters on the spinning performance was thus provided. The experimental results showed that the morphology of micro/nano-fibers can be well controlled by adjusting the spinning process parameters. Ultrafine PVA fibers with the diameter of 2.55 μm were successfully obtained applying the parameters, including rotation speed (6500 rpm), needle size (0.51 mm), feeding rate (3000 mL h−1), and voltage (20 kV). Furthermore, the obtained ultrafine PVA fiber mat was demonstrated to be capable of selectively adsorbing NH3gas relative to CO2, thus making it promising for NH3storage and other environmental purification applications.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Hanzi Liu,Changfu You,Haiming Wang
Transient in-situ IR spectroscopy was performed to analyze the molecular behavior of selective catalytic reduction of NO with NH 3 on V 2 O 5 -WO 3 /TiO 2 catalyst. During NH 3 adsorption, an unexpected growth in the intensity of Lewis acid sites was observed due to the hydrogen migration, which was verified by the DFT calculation and the existence of intermediate species. The comparison between the isolated atmosphere experiments and the simultaneous exposure of NH 3 -NO-O 2 on catalytic monolayer demonstrated that: (i) there exists a pathway for Lewis to Brønsted acid sites transformation at T > 300 °C, (ii) the rate determining step of the SCR cycle involves in the re-oxidation of acid sites by O 2 at 200–300 °C. Generally, the Lewis acids are crucial at high temperatures, while Brønsted acids dominate the overall reaction at lower temperatures. Based on the experimental data and the DFT calculation, a mechanism for ammonia adsorption, acidity conversion and re-oxidation for the redox loop of the de-NOx reaction was proposed. The findings shed light on the understanding of relative strength of NO reduction and acid re-oxidation at different temperatures.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Progress & Sustainable Energy
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2013
·Vol. 33
·期 2
·385-389
·
IF 0.865
Wei-guo Pan,Yue Zhou,Rui-tang Guo,Wen-long Zhen,Jie-nan Hong,Hong-jian Xu,Qiang Jin,Cheng-gang Ding,Shi-yi Guo
CeO-CuO catalysts were prepared by citric acid method at different calcination temperatures. The purpose of this study is to investigate the influence of calcination temperature on the catalytic activity of CeO 2 -CuO catalyst for the selective catalytic reduction of NO with NH 3 . As can be seen from the results, Ce-Cu(450) is of the best low temperature selective catalytic reduction (SCR) activity among the three catalysts, which may be resulted from its large surface area, good redox ability, strong NH 3 adsorption capacity, and high concentration of Cu 2+ and active oxygen species on the surface. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 385–389, 2014
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Cheng Shen,Peng Wang,Laihong Shen,Xianglei Yin,Zhenwu Miao
Alkaline earth metal chlorides (AEMH) are considered to be the key to effectively solving the problem of NH3 storage due to their ability to react with NH3 to form stable ammonia complexes. This study attempted to investigate the NH3 adsorption performance of four metal chlorides (CuCl2, MnCl2, MgCl2, and CaCl2) and silicon-supported composite adsorbents with a fixed bed. The adsorbents were characterized by X-ray diffraction, Brunauer–Emmett–Teller, and scanning electron microscopy to analyze the NH3 adsorption behavior. The experiment found that the NH3 adsorption capacity of four metal chlorides is in order: CuCl2 > MnCl2 > MgCl2 > CaCl2, and the adsorption capacity of metal chlorides decreased with the increase in temperature. In addition, the composite adsorbents of silicon-supported metal chlorides were synthesized by the wet impregnation method. Ammonia adsorption experiments showed that silicon can significantly improve the NH3 adsorption capacity of metal chlorides, and the NH3 adsorption capacity of MnCl2/silicon was 127.5% higher than that of MnCl2. Silicon played the role of the skeleton support in the metal chloride particles, hindering the agglomeration between particles and increasing the number of pores on the surface of the particles, which was conducive to the diffusion of NH3 through the pores into the particles for adsorption.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2014
·
IF 1.197
Rui-tang Guo,Wen-long Zhen,Wei-guo Pan,Jie-nan Hong,Qiang Jin,Cheng-gang Ding,Shi-yi Guo
CeO2–CuO/Al2O3 catalysts were prepared by three different methods and their activities for selective catalytic reduction (SCR) of NO with NH3 were investigated. As can be seen from the experimental results, the catalyst prepared by the single-step sol–gel (SG) method showed the best SCR activity and resistance to SO2 and H2O. In order to investigate the relationship between the preparation method and the performance of SCR catalysts, the catalysts were characterized by using Brunauer–Emmett–Teller, X-ray diffraction, temperature programmed reduction with hydrogen, temperature programmed desorption with ammonia, X-ray photoelectron spectroscopy, Fourier transform infrared and thermo-gravimetric analysis techniques. It was found that the excellent performance of CeO2–CuO/Al2O3 catalyst prepared by the single-step SG method should be resulted from its large surface area, low crystallinity, high oxygen storage capacity, high NH3 adsorption capacity, high concentration of surface chemisorbed oxygen, weak sulphation process and weak water absorption.
研究领域:
环境科学
·
催化材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2013
·
IF 2.145
Rui-tang Guo,Yue Zhou,Wei-guo Pan,Jie-nan Hong,Wen-long Zhen,Qiang Jin,Cheng-gang Ding,Shi-yi Guo
CeO 2 /Al 2 O 3 catalysts prepared by three methods were investigated for selective reduction of NO with NH 3 . It was found that the catalyst prepared by the single step sol–gel method had the best SCR activity and SO 2 resistance performance. From the results of BET, XRD, TPD and TPR, it can be concluded that large surface area, strong interaction, highly dispersed nano-crystalline ceria , high NH 3 adsorption capacity and good redox ability might be the main reasons for the excellent performance of CeO 2 /Al 2 O 3 catalyst prepared by the single step sol–gel method.
研究领域:
催化
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 10
·5608-5616
·
IF 7.443
Chan Wang,Miao Yang,Peng Tian,Shutao Xu,Yue Yang,Dehua Wang,Yangyang Yuan,Zhongmin Liu
A spherical self-assembly of SAPO-34 nanosheets was hydrothermally synthesized by using a quaternary ammonium-type organosilane surfactant [3-(trimethoxysilyl)propyl]octadecyldimethylammonium chloride (TPOAC) as the mesoporogen and a part of the silica source, and diethylamine (DEA) as the microporous template. The prepared materials were well characterized by XRD, XRF, SEM, TEM, N2 adsorption–desorption, NH3-TPD, NH3-adsorbed IR and pyridine-adsorbed IR measurements. It revealed that the morphologies, compositions and acidity of the SAPO-34 products changed significantly with the increased TPOAC/TEOS ratio, showing that the TPOAC/TEOS ratio had a significant impact on the crystallization process of SAPO-34. Solid state 13C, 29Si NMR and TG-DTA analyses were further conducted to investigate the status of TPOAC in the final products. A possible crystallization process involving TPOAC was proposed. The catalytic performances of the synthesized SAPO-34s were evaluated using the MTO reaction. The optimal SAPO-34 nanosheet assemblies with a hierarchical porous structure displayed a remarkably enhanced catalytic lifetime and high yields of light olefins.
研究领域:
材料科学
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化学工程
·
催化
·
无机化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）