ENERGY & FUELS
·
2018
·
IF 3.024
Na Rao,Mei Wang,Ziming Shang,Yanwen Hou,Guozhi Fan,Jianfen Li
Modifications by impregnation and grafting are commonly used for the preparation of amine-functionalized MCM-41. A comprehensive evaluation of the advantages and disadvantages of the two methods was performed in this work. MCM-41 was synthesized by the hydrothermal method, setting the amine-loading mass fraction at 40, 50, and 60 wt %. Three amine-modified adsorbents were prepared by impregnating polyethylenimine (PEI), and the three other adsorbents were prepared by grafting 3-aminopropyltriethoxysilane (APTS) onto MCM-41. The as-prepared adsorbents were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and N2 adsorption–desorption techniques. CO2 adsorption capacities were measured, and the experimental data were fitted with adsorption kinetic models. The cyclic stability of the adsorbents prepared by the two kinds of amine-modified methods was compared using the cyclic adsorption–desorption experiments. The characterization results showed that the target adsorbents were prepared successfully. The thermal stability of the adsorbents modified by grafting was better than the thermal stability of the adsorbents modified by the impregnation. Maximum CO2 adsorption capacities of 3.53 mmol g–1 (50% PEI–MCM-41) and 2.41 mmol g–1 (50% APTS–MCM-41) could be reached at 25 °C and 1 atm, which were 4.7 and 3.2 times greater than that of MCM-41. The Avrami model fitted the experimental data well, indicating a variety of interactions between the adsorbents and CO2. CO2 adsorption capacity after 5 adsorption–desorption cycles decreased by 14.22 and 5.19% for the adsorbents prepared by impregnation and grafting, respectively. It was concluded that MCM-41 modified by impregnation and grafting followed the same kinetic model. The absorbents modified by impregnation showed higher CO2 adsorption capacity and amine-loading efficiency, while those prepared by grafting had better thermal and cyclic stabilities.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Leiqing Hu,Jun Cheng,Yannan Li,Jianzhong Liu,Li Zhang,Junhu Zhou,Kefa Cen
Mixed matrix membranes with ionic liquids and molecular sieve particles had high CO 2 permeabilities, but CO 2 separation from small gas molecules such as H 2 was dissatisfied because of bad interfacial interaction between ionic liquid and molecular sieve particles. To solve that, amine groups were introduced to modify surface of molecular sieve particles before loading with ionic liquid. SAPO 34 was adopted as the original filler, and four mixed matrix membranes with different fillers were prepared on the outer surface of ceramic hollow fibers. Both surface voids and hard agglomerations disappeared, and the surface became smooth after SAPO 34 was modified by amine groups and ionic liquid [P 66614 ][2-Op]. Mixed matrix membranes with composites of amine-modified SAPO 34 and ionic liquid exhibited excellent CO 2 permeability (408.9 Barrers) and CO 2 /H 2 selectivity (22.1).
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Atmospheric Pollution Research
·
2018
·
IF 2.152
Xiao Yu,Jinliang Hao,Zhicheng Xi,Taiyang Liu,Ying Lin,Bin Xu
Three amine-modified Merrifield resins (AMMRs) were synthesized with ethane diamine, methylamine and dimethylamine to assess the impact of amine group on SO 2 adsorption under low SO 2 concentration. The dimethylamine-modified Merrifield resin (DMAMR) grafting with tertiary amine groups showed the greatest SO 2 adsorption compared with ethane diamine-modified Merrifield resin (EDAMR) and methylamine-modified Merrifield resin (MAMR). Different amine groups had different reaction mechanisms with SO 2 . It was much easier for SO 2 to form noncovalent charge transfer complex with tertiary amine group than the zwitterion and ion/counterion products with primary and secondary amine groups under dry condition. The noncovalent charge transfer complex had a relatively weaker thermostability than the zwitterion and ion/counterion products. As the temperature increased from 25 °C to 75 °C, the SO 2 adsorption capacity on DMAMR decreased by 78.92%, which was much higher than that of EDAMR and MAMR (63.77% and 63.41% respectively). As SO 2 concentration increased from 40 ppm to 100 ppm, significant increase (∼100%) in SO 2 adsorption capacity was observed. Lower SO 2 flow rate led to a more sufficient reaction between SO 2 and amine groups, resulting the increase in SO 2 adsorption capacities. Water vapor enhanced the SO 2 adsorption performance of AMMRs significantly due to the formation of salt. However, it was more difficult for tertiary amine group to react with SO 2 in the presence of water due to its relatively weaker basicity . DMAMR showed a greater regeneration performance than EDAMR and MAMR under dry and humid condition.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
SOLID STATE SCIENCES
·
2024
·
IF 3.4
Dong Yanping,Xiqiang Tian,Hongji Zhao,Jintao Luo
The fabrication of small Pd nanoparticles (NPs) anchored on titanium dioxide (TiO 2 ) supports remains a great challenge due to its high surface energy. Herein, flower-like three dimensional (3D) TiO 2 microstructures assembled from needle flakes are fabricated thru a facile evaporation-induced assisted hydrothermal method, and then modified with amines group (3D-TiO 2 -NH 2 ). Small and uniform dispersed Pd nanoparticles were anchored on the surface of 3D-TiO 2 -NH 2 supports using polyol reduction method. Remarkably, the obtained 3D-TiO 2 -NH 2 supported Pd-based catalyst (Pd@3D-TiO 2 -NH 2 ) demonstrated an optimal 4-NP catalytic hydrogenation efficiency ( k = 1.09 min −1 ), which is 1.56 and 3.52 times superior than that of the Pd@3D-TiO 2 ( k = 0.699 min −1 ) and Pd@TiO 2 –P25 ( k = 0.31 min −1 ) catalysts, respectively. In-depth investigation of the structure-property relationship by SEM, XRD, N 2 adsorption-desorption isotherm, TEM, XPS, CO chemisorption and CO-FTIR reveal that the optimal catalytic hydrogenation activity of Pd@3D-TiO 2 -NH 2 can be credited to its 3D hierarchical structure (interconnected needle flakes) and the amines group existing on the surface of flower-like three dimensional hierarchical TiO 2 , which control the Pd particles size (2.7 nm) and uniform dispersion (43.5%) to generate more surface active Pd 0 entities over Pd@3D-TiO 2 -NH 2 .
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Shuchen Tu,Fengzhu Lv,Pan Hu,Zilin Meng,Hongtao Ran,Yihe Zhang
Secondary and primary amines containing silica foams (F–SiO 2 ) were prepared by using silane coupling agents, (3-aminopropyl) triethoxysilane (KH-550) and bis(3-triethoxysilicyl propyl)-amine (KH-270), as modifiers. Not only Brunauer–Emmett–Tell (BET) surface and pore size of F–SiO 2 are greatly reduced after modification, but also increased chemical oxygen demand (COD) removal efficiency to trinitrotoluene (TNT) red water is obtained. Among the series of F–SiO 2 , the secondary amine modified silica foams possess higher COD removal capacity. Controlled experiments indicate the adsorption mainly derives from the attraction of amine groups toward the negative organic pollutants in TNT red water rather than the effect of the large BET surface and hydroxyl groups on the surface of F–SiO 2 . The adsorption model studies show the pseudo-second-order dynamic adsorption model and Langmuir isotherm model well fit the experimental data. The prepared amine-modified F–SiO 2 is an efficient adsorbents of organic pollutants in TNT red water.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2015
·Vol. 23
·期 2
·529-537
·
IF 1.108
Ma Beibei,Zhuang Linzhou,Chen Shuixia
The well-ordered hexagonal short-pore SBA-15 (SSBA-15) has been successfully synthesized via an energy-efficient process under the microwave-hydrothermal condition, in which the formation duration [stirring duration (ripening step) and microwave-hydrothermal treatment duration (aging step)] has been greatly decreased from 48 h for conventional hydrothermal treatment to <2 h. The extension of the ripening duration led to the evidently improved uniformity and regularity of particles while the increase of aging duration resulted in less intrawall pores and more structural mesopores. The optimal condition to get highly ordered SSBA-15 in this work was the duration of 2 h for both steps, and the SSBA-15 obtained was composed of cuboid-like particles, whose pore length was ca. 450 ± 50 nm and pore size was around 10 nm. The SSBA-15 was modified with different amine agents to prepare solid amine adsorbent, the obtained adsorbents showed considerable CO 2 adsorption ability, indicating that this fast-prepared SSBA-15 can be a promising support of CO 2 adsorbents.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 3
·1727-1737
·
IF 4.682
Wu Jingjie,Qiu Xianyu,Chen Shuixia
Abstract A 3D porous graphene aerogel (GA) was prepared via one-step hydrothermal method and freeze-drying technology, in which organic amine reagents were used as cross-linker to combine the graphene oxide (GO) sheets. With abundant amino groups, the organic amine reagents also acted as adsorption sites to improve CO 2 adsorption capacity. Morphology, pore structure and surface chemical structure of the as-prepared materials were characterized by SEM, FTIR, XRD, Raman, TG, N 2 adsorption–desorption. CO 2 adsorption performance was evaluated by dynamic adsorption experiments in a fixed-bed column. Aminated by tetraethylenepentamine (TEPA), the prepared 3D graphene aerogel (TEPA-GA-3–1) achieved a CO 2 adsorption capacity as high as 2.27 mmol g −1 at 25 °C, 0.1 bar, which was attributed to its developed porous structure and high amino density. Further, the existence of water could improve the CO 2 adsorption amount because H 2 O directly participates the reaction of CO 2 with amine to form bicarbonates. The prepared GA adsorbent also exhibited good stability after six adsorption–desorption cycles. The above result suggests that amine-modified graphene aerogel has a potential application for CO 2 capture from flue gas. Graphical abstract
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 33
·期 11
·e5198
·
IF 3.259
Yu Ru,Yanli Huang,Yuanyuan Wang,Liyi Dai
Well distributed Pd-Cu bimetallic alloy nanoparticles supported on amine-terminated ionic liquid functional three-dimensional graphene (3D IL-rGO/Pd-Cu) as an efficient catalyst for Suzuki cross-coupling reaction has been prepared via a facile synthetic method. The introduction of IL-NH 2 cations on the surface of graphene sheets can effectively avoid the re-deposition of graphene sheets, allowing the catalyst to be reused up to 10 cycles. The addition of Cu not only saves cost but also ensures high catalytic efficiency. It is worthy to note that the catalyst 3D IL-rGO/Pd 2.5 Cu 2.5 can efficiently catalyze the Suzuki cross-coupling reaction with the yield up to 100% in 0.25 h, almost one-fold higher than that by the pristine IL-rGO/Pd 2.5 catalyst (52%). The Powder X-Ray Diffraction (XRD), combining energy dispersive X-ray spectroscopy (EDS) mapping results confirm the existence and distribution of Pd and Cu in the bimetallic nanoparticles. The transmission electron microscopy (TEM) reveals the nanoparticle size with an average diameter of 3.0 ± 0.5 nm. X-ray photoelectron spectroscopy (XPS) analysis proved the presence of electron transfer from Cu to Pd upon alloying. Such alloying-induced electronic modification of Pd-Cu alloy and 3D ionic liquid functional graphene with large specific surface area both accounted for the catalytic enhancement.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2021
·Vol. 15
·期 4
·984-997
·
IF 4.204
Li Fengli,Chen Chuang,Wang Yuda,Li Wenpeng,Zhou Guoli,Zhang Haoqin,Zhang Jie,Wang Jingtao
Nanofibers with high specific surface area and chemical stability have broad prospects in the applications of adsorption. However, the adsorption capacity is limited by the scarcity of adsorption groups and storage space. Herein, the activated carbon-hybridized and amine-modified nanofibers are prepared by integrating activated carbon (AC) and polyacrylonitrile (PAN) via electrospinning method and the subsequent amination, which could provide additional storage space and adsorption groups for ultrahigh adsorption capability. Thus, the obtained aminerich porous PAN nanofibers (APAN/AC) readily realized the ultrahigh adsorption capacity for metal ions and dyes in wastewater. Specifically, the adsorption capacity of APAN/AC nanofibers were 284 mg·g −1 for Cr(VI) and 248 mg·g −1 for methyl orange, which were almost 2 and 4 times than that of amine-modified nanofibers (APAN) and carbon-hybridized nanofibers (PAN/AC), respectively. Moreover, the AC inhibited the chain mobility of polymer matrix and thereby endowing APAN/AC nanofibers with excellent recyclability. The adsorption capability retained 80% after nine adsorption-desorption cycles. The adsorption kinetics and corresponding mechanism were further explored. This strategy combines the advantages of polymer nanofibers and AC, opening a new avenue for developing next-generation absorbent materials.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Inorganics
·
2022
·Vol. 10
·期 7
·87
·
IF 3.149
Xiaoqi Jin,Jinlong Ge,Liyuan Zhang,Zhong Wu,Linlin Zhu,Mingwen Xiong
Hierarchically ordered porous silica materials (HSMs) with a micro/mesoporous structure were successfully prepared with the sol-gel method using dextran, dextran/CTAB, and CTAB as templates. The obtained hierarchically structured silica was successfully modified with amine groups through post-grafting and one-pot methods. Their architectural features and texture parameters were characterized by XRD, N2adsorption–desorption isotherms, SEM, TEM, FTIR, and TGA techniques. The results demonstrated that the pore structure depended on the reaction temperature and the amount of CTAB added in the synthesis procedure. A series of porous silica with hierarchical pore structures possessed abundant micropores, ordered mesopores, and a tunable surface area and pore volume. After modification, the ordered structure of the hierarchical porous silica almost disappeared due to the presence of amine groups in the pore channel. Furthermore, to explore the effect of pore structures and amine groups on CO2adsorption performance, before and after amine modification of HSMs, adsorbents were evaluated regarding the capacity of collecting CO2for comparison. According to these results, the varying microporous content, pore size distribution, and density of the amine groups were important factors determining the capacity of CO2capture.Keywords:hierarchically ordered porous silica;dextran template;amine group modification;CO2capture
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Entong Ye,Fangmei Lin,Chengbin Fu,Xin Zhou,Qian Lin,Hongyan Pan,Zheng Chen
A great deal of research has been carried out on the design of Pd-based catalysts in the direct synthesis of H2O2, mainly for the purpose of improving the H2O2 selectivity by weakening the activation energy on the Pd active site and thus inhibiting the dissociation of the O–O bonds in O2*, OOH*, and HOOH*. However, this often results in insufficient activation energy for the reaction between H2 and O2 on Pd, leading to difficulties in improving both the selectivity and productivity of H2O2 simultaneously. Based on this, this study reports an efficient catalyst composed of amine-functionalized SBA-15-supported Pd. The strong metal–support interaction not only makes the PdNPs highly dispersed with more Pd active sites but also improves the stability of the catalyst. The amine group modification increases the proportion of Pd0, further enhancing Pd activity and promoting the adsorption and conversion of H2 and O2 on Pd, thereby significantly increasing H2O2 productivity. Additionally, the density-functional theory simulation results showed that due to the hydrogen-bonding force between the amine group and H2O2, this particular anchoring effect would make the hydrogenation and decomposition of H2O2 effectively suppressed. Ultimately, both the selectivity and productivity of H2O2 are improved simultaneously.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY
·
2019
·Vol. 25
·期 4
·693-701
·
IF 1.731
Kuang Yizhu,He Hui,Chen Shuixia,Wu Jingjie,Liu Fenglei
Using efficient and stable solid amine adsorbents to capture CO 2 has been considered as an effective technology to reduce the CO 2 concentration in the atmosphere. In this paper, a series of solid amine-containing fibrous adsorbent for CO 2 capture were prepared by direct modification of polyacrylonitrile (PAN) fibers with amination reagents, including diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and polyethyleneimine (PEI). Abundant amine groups can be introduced on the PAN surface owing to the reactivity between cyano group and amino group. The effects of the type and structure of amination reagents on the swelling properties and CO 2 adsorption capacities of the as-prepared adsorbents were investigated. The results indicated that chemical modification of PAN fibers with amine compounds could greatly increase the CO 2 adsorption capacity of the aminated adsorbents. The adsorption capacities of the adsorbents were correlated well with the content of amino groups. PAN–TETA and PAN–TEPA showed higher CO 2 adsorption capacities and better stability than PAN–DETA and PAN–PEI. Besides, as water molecules could take part in and facilitate the CO 2 adsorption, the CO 2 adsorption capacity of amine-modified fibers would be strongly dependent on the swelling property.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）