CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Peng Liu,Mengmeng Chen,Yiqiang Ma,Chuan Hu,Qiugen Zhang,Aimei Zhu,Qinglin Liu
Pervaporation is a promising membrane technology for separation of aqueous organic solution particularly azeotrope and close-boiling point compounds. However, most of pervaporation membranes are based on hydrophilic polymers that suffer decline of separation performance due to their swelling in aqueous solution. Here we present a copolymer synthetic strategy for preparation of hydrophobic polymer pervaporation membrane with hierarchical porosity via uniting both rigid and flexible segments. The synthesized membrane has well-defined micropores and high free volume faction of 8.03% with cavity size of 0.476 nm, and demonstrate exceptional performance with high permeability and selectivity for dehydration of alcohols. In the pervaporation of ethanol-water azeotrope, the membrane displays the high permeabtion flux of 74.6 μm kg m −2 h −1 and water selectivity of 34 (separation factor of 732) at 30 °C. The developed strategy has excellent potential for synthesizing copolymers for high-efficient pervaporation membranes.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 7
·1432
·
IF 4.2
Tong Li,Shuangwei Wang,Jinqiang Gao,Ruiqiang Wang,Guifeng Gao,Guangming Ren,Shengnan Na,Mei Hong,Shihe Yang
Zeolite microspheres have been successfully applied in commercial-scale separators such as oxygen concentrators. However, further enhancement of their applications is hampered by the post-synthetic shaping process that formulates the zeolite powder into packing-sized spherical bodies with various binders leading to active site blockage and suboptimal performance. Herein, binderless zeolite microspheres with a tunable broad size range from 2 µm to 500 µm have been developed with high crystallinity, sphericity over 92%, monodispersity with a coefficient of variation (CV) less than 5%, and hierarchical pore architecture. Combining precursor impregnation and steam-assisted crystallization (SAC), mesoporous silica microspheres with a wide size range could be successfully transformed into zeolite. For preserved size and spherical morphology, a judicious selection of the synthesis conditions is crucial to ensure a pure phase, high crystallinity, and hierarchical architecture. For the sub-2-µm zeolite microsphere, low-temperature prolonged aging was important so as to suppress external zeolization that led to a large, single macroporous crystal. For the large 500 µm sphere, ultrasound pretreatment and vacuum impregnation were crucial and facilitated spatially uniform gel matrix dispersion and homogenous crystallization. The obtained zeolite 5A microspheres exhibited excellent air separation performance, while the 4A microspheres displayed ammonium removal capabilities. This work provides a general strategy to overcome the existing limitations in fabricating binder-free technical bodies of zeolites for various applications.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 25
·16257-16266
·
IF 4.036
Xuan Xiao,Lei Song,Qianli Wang,Zhicheng Wang,Hongyan Wang,Juncai Chu,Jianmin Liu,Xinru Liu,Zhentao Bian,Xuanxuan Zhao
In this paper, hollow-tubular porous carbons were synthesized from abundant biomass Cycas fluff (CF) through simple carbonization followed by an NaHCO3 mild activation process. After activation, the tubular structure of the CF was retained, and a hierarchical structure of micropores, mesopores and macropores was formed. When the optimal mass ratio of NaHCO3/CF is 2, the obtained porous carbon CF-HPC-2 sample has a large specific surface area (SSA) of 516.70 m2 g−1 in Brunauer–Emmett–Teller (BET) tests and a total pore volume of 0.33 cm3 g−1. The C, O, N and S contents of CF-HPC-2 were tested as 91.77 at%, 4.09 at%, 3.54 at%, and 0.6 at%, respectively, by elemental analysis. Remarkably, CF-HPC-2 exhibits a high volume capacitance (349.1 F cm−3 at 1 A g−1) as well as a higher rate capability than other biomass carbon materials (289.1 F cm−3 at 10 A g−1). Additionally, the energy density of the CF-HPC-2 based symmetric supercapacitor in 2 M Na2SO4 electrolyte at 20 kW kg−1 is 27.72 W h kg−1. The particular hollow tubular morphology and activated porous structure determine the excellent electrochemical performance of the material. Hence, this synthetic method provides a new way of storing energy for porous carbon as high volumetric capacitance supercapacitor materials.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Xuewen Chen,Hongping Quan,Zhengyan Zhou,Xiaofeng Zhang,Yuling Hu,Zhiyu Huang
In recent years, nanoporous materials with special structure have been widely used in various fields. In view of the poor stability of MOFs materials and the poor mass transfer ability, in this study, we developed a simple method to restrict the growth of UiO-66-NH 2 crystals in hollow silica by “vacuum evaporation” strategy, different kinds of acid regulators were introduced, to obtain a composite material with hierarchical pore structure. By characterizing the physical chemistry and microstructure of the composite adsorbent, and calculating the structural defects under different acid regulation, the adsorption and desorption performance and stability of the adsorbent for CO 2 were comprehensively investigated. The mechanism of action on CO 2 was further analyzed by in-situ infrared and other techniques. The results show that the change of coordination environment and coordination rate caused by the competition of organic acids, which increases the defects and reduces the nucleation and aggregation effect of UiO-66-NH 2 , promotes the formation of hierarchical pore structure of the composites. Among them, benzoic acid is the best regulating monocarboxylic acid, which makes UiO-66-NH 2 have good dispersion in the cavity and suitable crystal size. The specific surface area of the composite material is 717.96 m 2 g −1 . At the same time, due to its excellent CO 2 adsorption capacity (3.35 mmol g −1 ) at 298 K and 1.06 bar, it is 48.07 % higher than the original UiO-66-NH 2 . In order to accomplish the goal of effective CO2 adsorption performance of composites, this study offers a novel approach for the synthesis and modification of MOFs-based composites.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Xinhui Liu,Chen Yan,Yilin Wang,Peng Zhang,Siyan Yan,Hanbin Wang,Jianguo Zhuang,Yitao Zhao,Yuchen Wang,Yijun Yu,Qichao Zhao,Xuedong Zhu,Fan Yang
A series of Zn loaded ZSM-5 (Zn/ZSM-5) zeolites were prepared utilizing either Zn(NO 3 ) 2 or Zn-based MOFs (ZIF-61, ZIF-8 and ZIF-14) as Zn sources to explore their effects on the catalysts’ physiochemical properties through characterizations and simulations. Results revealed that hierarchical structures containing meso - to macro- pores of 10 ∼ 80 nm aside from the intrinsic micropores were constructed profiting from the use of Zn-based MOFs. On the other side, lager proportions of medium acid and Lewis acid sites were generated by more Zn(OH) + , whose content was proven to be inextricably linked to the binding energy between Zn and ligand as well as local charge valence state of Zn. Benefitting from hierarchical structures and balanced acidities, Zn/Z5(ZIF-14) employing ZIF-14 as Zn source demonstrated higher aromatic selectivity and longer catalyst lifetime (50.9 % and 26 h) than the microporous counterpart synthesized from zinc nitrate hexahydrate (42.1 % and 20 h) in methanol to aromatics (MTA) reaction.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of the American Chemical Society
·
2023
·
IF 15
Shang Shi,Zhenzhen Shen,Shanshan Li,Qian Wang,Rui Wen,Bing Liu
The use of carbon materials in porous electrodes has impressive advantages. However, precisely tailoring the multilevel pore structure of carbon electrodes remains an unsolved challenge. Here, we report a highly efficient site-selective growth strategy to synthesize colloidal carbon rings by templating patchy droplets. Carbon rings are used for the direct fabrication of self-standing porous electrodes with hierarchical pores for lithium–oxygen batteries (LOBs). In situ atomic force microscopy reveals that during discharge the discharge products densely nucleate and grow on carbon rings, demonstrating that such rings are a very potential electrode material in LOBs. The hollow carbon ring electrode (HCRE) possesses micrometer-scale channels formed by random packing of rings and nanochannels consisting of ring-shaped hollow cavities connected by nanosized pores in the wall. Both channels contribute to ion transportation and gas diffusion, but the storage of the discharge products mainly lies in micrometer-scale channels, leading to a high discharge capacity of LOBs (20 658 mAh/g). Our work paves a new way to construct hierarchically porous electrodes for application in electrocatalysis and electrochemical energy storage.
研究领域:
材料科学
·
电化学能源存储
✓ 已验证
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2024
·
IF 2.5
Zhang Yanting
Both seed solution and Cetyltrimethylammonium bromide(CTAB) serve as common template agents in the synthesis of hierarchical ZSM-5 zeolites. However, their specific roles in the synthesis process have not been clearly understood. In this study, hierarchical ZSM-5 zeolites were successfully synthesized using a 1.5% mass fraction (relative to the silicon source) seed solution in combination with varying amounts of CTAB. The physical and chemical properties of the hierarchical ZSM-5 zeolites were characterized using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), low-temperature N 2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG), ammonia temperature-programmed desorption (NH 3 -TPD), pyridine-IR, and 2,4,6-collidine-IR. The investigation revealed that the CTAB content significantly influenced the synthesis of hierarchical ZSM-5 zeolites, with CTAB contributing to framework filling, charge balancing, and acting as a mesoporous template during the synthesis process, while the seed solution primarily served as a structure-directing agent. Moreover, utilizing the conversion of C8 aromatic hydrocarbons as a probe reaction, it was demonstrated that ZSM-5 zeolites synthesized with the co-assistance of seeds and CTAB exhibited enhanced conversion for ethylbenzene and m-xylene compared to samples synthesized exclusively with a seed solution.
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
Industrial Chemistry & Materials
·
2022
·Vol. 1
·期 1
·106-116
·
IF 0
Wen Yao,Chenghong Hu,Yajie Zhang,Hao Li,Fengliang Wang,Kui Shen,Liyu Chen,Yingwei Li
Nitrogen-rich zeolitic imidazolate frameworks (ZIFs) are ideal precursors for the synthesis of metal single atoms anchored on N-doped carbon. However, the microporous structures of conventional ZIFs lead to low mass transfer efficiency and low metal utilization of their derivatives. Here, we construct a composite of Co single atoms anchored on nitrogen-doped carbon with a three-dimensional ordered macroporous structure (Co-SA/3DOM-NC) by two-step pyrolysis of ordered macro/microporous ZnCo-ZIF. Co-SA/3DOM-NC shows high activity in the oxidative esterification of furfural, achieving a 99% yield of methyl 2-furoate under mild reaction conditions, which is significantly superior to the microporous and the Co-nanoparticle counterparts. The high activity of Co-SA/3DOM-NC should be attributed to the CoN4 centers with high intrinsic activity and the ordered macroporous structure, promoting the mass transfer of reactants and accessibility of active sites.
Keywords: Heterogeneous catalysis; Hierarchical pores; Ordered macropore; Oxidative esterification reaction; Single-atom catalysts.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Lei Wang,Yukun Ma,Huili Liu,Yanzhen Guo,Baocheng Yang,Binbin Chang
Leveraging porosity, surface chemistry and morphology of porous carbons plays a critical role in CO 2 capture performance. However, the effective and sustainable synthesis of porous carbons with well-interconnected hierarchical pore structure, high-proportioned micropores and high yield remains a huge challenging by a mild one-step chemical activation without damaging the natural unique nanostructure. Here, we proposed a green and sustainable strategy to fabricate porous carbons with tailorable porosity and unique tubular structure by an inorganic dynamic porogen of CuCl 2 . The dynamic activation mechanism of CuCl 2 was explored in detail. In particular, the hierarchical porosity with a high-proportioned narrow micropores can be finely tuned without sacrificing the natural tubular morphology. Importantly, the resultant porous carbon adsorbents have an excellent resistance to water vapor, which can capture CO 2 from humid flue gases with satisfactory adsorption capacity and selectivity. The HPCM-3 can achieve the best CO 2 uptakes of 4.05 and 2.05 mmol/g under 100 kPa at 25 and 50 °C, respectively. Such superior CO 2 adsorption behaviors can be well maintained even at high humidity of 70 %, and hardly decay with the enhancement of humidity. This route provides a promising avenue for developing the practical trace CO 2 carbon-based adsorbents on a large scale to sieve CO 2 from humid flue gases.
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
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Dingxuan Ma,Yaowen Zhang,Huihui Zhao,Kang Liu,Lei Wang
Porous organic frameworks (POFs) catalysts with a combination of the well-developed porosity and highly dispersed of active sites hold promise for boosting catalyst activity and selectivity. Among their many synthetic methods, one-step knitting strategies have gained superiority and potential for development. Here, two copper porphyrin based microporous polymers (SC-Cu and FC-Cu) were directly synthesized through Scholl coupling reaction and Friedel-Crafts alkylation reaction respectively, which possess high surface area and efficient catalytic performance for styrene oxidation. Moreover, the hierarchical pores of SC-Cu gave it a unique catalytic performance with various olefins with excellent conversion rate. The insight achieved by this systematic analysis will contribute to the rational design of other POFs catalysts and widening extent of applications.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2025
·
IF 9.4
Hei Xiao,Huicong Zhang,Fashe Li,Hua Wang
The adsorption desulfurization process of waste cooking oil biodiesel faces challenges such as low efficiency and susceptibility to oxidation. Drawing inspiration from the in-situ generation of hierarchical pores during the carbonization of biomass pyrolysis products, a novel zeolite template carbon was fabricated for deep adsorption desulfurization of biodiesel by integrating biomass pyrolysis with chemical vapor deposition. Experiments, simulations, and characterizations were conducted to analyze the formation mechanism of biomass-based zeolitetemplated carbon and its desulfurization performance. The results indicated the decomposition of carbonized precursors and the collapse of the 13X zeolite crystal structure were the primary factors driving the formation of hierarchical pores Under carbonization temperature of 900 °C and a holding time of 2 h, the biomass-based zeolite template carbon achieved optimal desulfurization performance, with an adsorption desulfurization efficiency exceeding 85 % and a sulfur content reduced to 5.10 ppm. Furthermore, dibenzothiophene was effectively trapped on the adsorbent through physical adsorption, and the high desulfurization performance can be attributed primarily to the formation of hierarchical pores. This study provides a method for constructing hierarchical porous carbon materials, offering a scientific foundation and technical support for overcoming the challenges of deep adsorption desulfurization in biodiesel.
研究领域:
能源材料
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Yinghui Xu,Xuan Zhao,Ran Chang,Hongqiang Qu,Jianzhong Xu,Jing Ma
Rationally regulating the separation pores is an effective way to achieve efficient separation membrane . However, the developed metal-organic framework (MOF) membranes for water treatment are all formed by one kind of MOF, which can only provide rigid pores, makes it difficult to achieve high flux and excellent rejection ratio simultaneity. Here, we proposed a facile strategy for the synthesis of heterogeneous MOF-on-MOF membrane with hierarchical pores, by site-specific grown ZIF-8 layer on UiO-66-NH 2 layer. Thus unique architecture of the obtained double-layered MOF membrane (UiO-66-NH 2 @ZIF-8) endows multidimensional separation pores: (i) the large pores of UiO-66-NH 2 can facilitate water transportation, (ii) the molecular-sieving pores of ZIF-8 can intercept dyes, (iii) UiO-66-NH 2 acting as active sites can promote the growth of ZIF-8. As a result, the optimized UiO-66-NH 2 @ZIF-8 membrane exhibits high flux (36.7 L m −2 h −1 bar −1 ) and excellent dye rejections (>97.0%). Through analysis and comparison, the regulated multi-type pores play an important role in membrane performance. Coupled with the facile membrane preparing method, this work can used as a potential approach of designing other advanced MOF membrane for water treatment.
研究领域:
材料科学
·
环境工程
·
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）