Catalysts
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2020
·Vol. 10
·期 3
·311
·
IF 3.52
Jing Shao,Shuyuan Cheng,Zhaoxu Li,Bichun Huang
A ZSM-5 zeolite with a hierarchical pore structure was synthesized by the desilication-recrystallization method using tetraethyl ammonium hydroxide (TEAOH) and cetyltrimethylammonium bromide (CTAB) as the desilication and structure-directing agents, respectively. The MnOx/ZSM-5 catalyst was synthesized by the ethanol dispersion method and applied for the low-temperature selective catalytic reduction of NOxwith NH3. The results showed that NOxconversion of the hierarchical MnOx/ZSM-5 catalyst could reach 100% at about 120 °C and could be maintained in the temperature range of 120–240 °C with N2selectivity over 90%. Furthermore, the hierarchical MnOx/ZSM-5catalyst presented better SO2resistance performance than the traditional catalyst in the presence of 100 ppm SO2at 120 °C. XRD, SEM, TEM, XPS, BET, NH3-TPD, and TG were applied to characterize the structural properties of the MnOx/ZSM-5 catalysts. These results showed that the MnOx/ZSM-5 catalyst had micropores (0.78 nm) and mesopores (3.2 nm) leading to a larger specific surface area, which improved the mass transfer of reactants and products while reducing the formation of sulfates. The better catalytic performance over hierarchical MnOx/ZSM-5 catalyst could be attributed to the higher concentration of Mn4+and chemisorbed oxygen species and higher surface acidity. The improved SO2resistance was related to the catalyst’s hierarchical pore structure.Keywords:hierarchical pore structure;MnOx/ZSM-5;NH3-SCR;SO2resistance
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Deshuang Lu,Zhonghan Cheng,Nikom Klomkliang,Wanida Koo-amornpattana,Francis Verpoort,Somboon Chaemchuen
Organic linkers are typically controlled to create the micropore structure when synthesizing metal-organic frameworks (MOFs). However, developing a hierarchical pore structure is beneficial for improving the efficiency of MOFs in various applications. This study investigates a green strategy using a water modulator that competes with the terephthalic ligand to coordinate with zirconium clusters, thereby accessing open sites for hierarchical micro- and mesopores in UiO-66. Using a hydro-modulator induced the formation of a mesoporous structure and enhanced the hydrophilic properties of UiO-66-X due to the presence of hydroxyl groups. Also, model calculations using density functional theory (DFT) support the observed structural chemical geometry. The advantages of a hierarchical pore structure, increased hydrophilicity, and the presence of open sites in the robust structure of UiO-66-X led to a significant enhancement in both antibiotic adsorption and the catalytic activity of ring-opening epoxide reactions compared to the pristine microporous UiO-66. Therefore, utilizing water as a green modulator presents a simple and environmentally friendly approach to introducing hierarchical pore structures in MOFs. It offers a promising strategy for enhancing their performance across 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
高影响因子
BIORESOURCE TECHNOLOGY
·
2024
·
IF 9.7
Qihang Wang,Jun Mu
Converting waste resource into porous carbon toward contaminant capturing is a crucial strategy for realizing “treating waste with waste”. Inspired by bread baking process, the soybean meal activated carbon (SAC) with multimodal pore structures was developed via thermally remodeling the pores of waste soybean meal. The obtained SAC-3-800 has ultra-high specific surface area (3536.952 m 2 /g), as well as a hierarchically porous structure. SAC-3-800 exhibits extremely high adsorption capacity for methylene blue (MB) (3015.59 mg/g), methyl orange (MO) (6486.30 mg/g), and mixed dyes (8475.09 mg/g). The hierarchically porous structure enabled fast adsorption kinetics of SAC-3-800 for MB and MO (∼30 min). Additionally, SAC-3-800 shows excellent dynamic adsorption and regeneration performance, exhibiting great potential for industrial applications. This work showcases a feasible method for synthesizing hierarchically porous carbon with outstanding adsorption performance that can simultaneously achieve efficient treatment of dye-wastewater and value-added utilization of waste resources.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Qin Zhu,Jiaorong Yan,Qiguang Dai,Qingqing Wu,Yuanpu Cai,Jinyan Wu,Xingyi Wang,Wangcheng Zhan
A unique zeolite catalyst, Fe doped ZSM-5 microsphere assembled by uniform nanorod-like crystals with hierarchical pore structure, was successfully synthesized and applied for the adsorption and degradation of trace chlorobenzene (CB) in the presence of H 2 O 2 . The organic ferric salts as the precursors, ethylene glycol as a chelating/reducing agent and the dynamic two-stage temperature-varied hydrothermal technique, together made the synthesized hierarchical Fe-ZSM-5 nanorods assembled microspheres (FZ-CA-5EG) to be characterized by abundant highly dispersed and valency-controlled framework Fe 3+/2+ species. As a result of these features, the FZ-CA-5EG showed excellent ability of adsorption and degradation efficiency of CB, and enhanced durability due to negligible leaching of framework Fe species. Moreover, the hydroxyl radicals were determined as the main the reactive oxygen species of CB oxidation degradation, and a possible adsorption-oxidation degradation pathway was proposed.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Jie-Ping Fan,Yu-Tong Cheng,Xue-Hong Zhang,Zhou-Peng Xiao,Dan-Dan Liao,Hui-Ping Chen,Kuan Huang,Hai-Long Peng
In this work, a novel mixed non-covalent and semi-covalent molecularly imprinted membrane (MIM) with hierarchical pores was prepared by cryopolymerization at −18 °C and using PEG2000 and dimethyl sulfoxide ice crystals as the pore templates. The free-standing MIM was characterized by scanning electron microscope and nitrogen adsorption-desorption isotherms, and the results confirmed the formation of the hierarchical pore structure . In the static adsorption, membrane permeation and dead-end filtration experiments, the results indicated that the mixed non-covalent and semi-covalent molecular imprinting was a good method to improve the performance of MIM which had a good adsorption selectivity toward genistein due to the presence of the imprinted sites in MIM and possessed strong imprinting efficiency toward genistein even in some similar compound mixture or extract of Radix Puerariae Lobatae.
研究领域:
药学
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分离科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2018
·Vol. 29
·期 13
·10689-10701
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IF 2.324
Wang Chenlong,Sun Ting,Zhang Xugang,Chu Mingna,Lv Shixian,Xiang Junyu,Wang JinShuang,Ma Yongjun,Qin Chuanli
It is highly desired to simultaneously introduce active heteroatoms and abundant hierarchical pore structures for enhanced electrochemical performances on carbon materials. Herein, trehalose as a pore-forming agent was added into polyvinylpyrrolidone/melamine formaldedyde resin mixture with high concentrations of nitrogen and oxygen. Then a simple one-step carbonization/activation process was adopted and heteroatom-enriched carbon with hierarchical pores (HPC) was fabricated successfully. HPC/HPC symmetric supercapacitors were assembled using KOH electrolyte. It is clearly demonstrated that due to the pore-forming action of trehalose HPC shows the porous honeycomb, interconnected and worm-like pore structure, which is favorable to enhance the double-layer capacitance. It is confirmed that in our system the three active species of pyridinic nitrogen (N-6), pyrrolic nitrogen (N-5) and quinone type oxygen (O-I) are responsible for the pseudocapacitive behavior. Based on XPS, nitrogen adsorption/desorption isotherms and electrochemical impedance spectroscopy, it is deduced that the ratio-optimized HPC-T30 exhibits high concentration of three active species (8.17 at.%), increased specific area (351.26 m 2 g −1 ) and tuned hierarchical pore structures with substantial micropores (micropore area of 321.68 m 2 g −1 ) and a small amount of mesopores and macropores, which lead to decrease of charge transfer resistance, increase of transfer rate of electrolyte ions in the pores and excellent electrochemical performances. In cyclic voltammetry tests of three-electrode system and galvanostatic charge/discharge tests of two-electrode system, HPC-T30 displays high specific capacitance, 46% and 1.2-time enhancement compared to untreated HPC-T0, respectively. The optimized HPC-T30/HPC-T30 supercapacitor delivers the energy density of 6.69 W h kg −1 in 6 M KOH electrolyte. Furthermore, the supercapacitor shows a capacitance retention of 91.16% up to 6000 cycles and the coulombic efficiency reaches nearly 100% for each charged/discharge cycle, demonstrating its good cyclic stability.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
·
IF 7.312
Chun-Ping Li,Ya-Qi Wu,Fei-Yang Zhang,Li-Xin Gao,Da-Quan Zhang,Zhong-Xun An
Carbon materials with suitable pore size distribution, high specific surface area and good wettability are crucial for the capacitive deionization (CDI) electrode. Herein, the Mg-MOF-74 derived carbon (MMCK) is prepared by solvothermal synthesis, carbonization, and potassium hydroxide (KOH) activation method. The MMCK has super hydrophilicity and rich hierarchical porous structure composed of micropores, mesopores and macropores. The capacitive deionization of MMCK is investigated in NaCl aqueous solution. The MMCK has high oxygen doping amount, and has a high electrosorption capacity (16.82 mg·g −1 ) for 500 mg·L −1 NaCl. This indicates that MMCK is novel and potential material for capacitive deionization.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2021
·Vol. 11
·期 3
·314
·
IF 4.146
Lusha Zhou,Jinkun Guan,Chenglong Yu,Bichun Huang
The ethanol dispersion method was employed to synthesize a series of MnOx/SAPO-34 catalysts using SAPO-34 with the hierarchical pore structure as the zeolite carrier, which were prepared by facile acid treatment with citric acid. Physicochemical properties of catalysts were characterized by XRD, XPS, BET, TEM, NH3-TPD, SEM, FT-IR, Py-IR, H2-TRP and TG/DTG. NH3-SCR performances of the hierarchical MnOx/SAPO-34 catalysts were evaluated at low temperatures. Results show that citric acid etching solution at a concentration of 0.1 mol/L yielded a hierarchical MnOx/SAPO-34-0.1 catalyst withca.15 wt.% Mn loading, exhibiting optimal catalytic activity and SO2tolerance at low temperatures. Almost 100% NO conversion and over 90% N2selectivity at 120 °C under a gas hourly space velocity (GHSV) of 40,000 h−1could be obtained over this sample. Furthermore, the NO conversion was still higher than 65% when 100 ppm SO2was introduced to the reaction gas for 4 h. These could be primarily attributed to the large specific surface area, high surface acidity concentration and abundant chemisorbed oxygen species provided by the hierarchical pore structure, which could also increase the mass transfer of the reaction gas. This finding suggests that the NH3-SCR activity and SO2poisoning tolerance of hierarchical MnOx/SAPO-34 catalysts at low temperatures can be improved by controlling the morphology of the catalysts, which might supply a rational strategy for the design and synthesis of Mn-based SCR catalysts.
研究领域:
催化化学
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环境科学
✓ 已验证
DOI
高影响因子
APPLIED ENERGY
·
2019
·
IF 8.426
Rui Wang,Yinshi Li,Yanning Wang,Zhou Fang
The redox flow battery technology is of great potential for large-scale energy storage. However, its widespread application is suffering from the challenges of low energy efficiency and considerable performance degradation in the high-current cycles. Herein, we propose and develop a phosphorus-doped electrode with stabilized electrochemical interface and hierarchical pore structure for cost-effective flow batteries. Density functional theory calculation was first used to demonstrate the stability and activity of phosphorus-doped graphite surface. On basis of theoretical design, the phosphorus-doped graphite felt electrode was fabricated by a facial thermally treating method. Stabilized heteroatom-doped chemical surface with abundant phosphorus-containing functional groups (1.7%) was observed. Beyond that, the hierarchical pore structure from macro (~20 μm) to nanoscale (<200 nm) was formed synchronously, suggesting the enhanced reaction activity, stability and mass transport. In charge-discharge test, flow battery assembled with phosphorus-doped electrodes yielded a prominent energy efficiency of 81% at 200 mA cm −2 , 46% higher than battery with traditional electrodes. Even current densities up to 500 mA cm −2 , battery with phosphorus-doped electrodes still exhibits a workable energy efficiency of 64% while batteries with other electrodes cannot operate properly. Moreover, the superior durability of battery with phosphorus-doped electrodes was verified after 100-cycle charge-discharge test with nearly no-decay energy efficiencies. This work offers a promising way to develop stable and efficient flow batteries for the energy storage systems.
研究领域:
材料科学
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电化学
·
能源存储
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Peng Zhang,Yueyang Xu,Konglu Guo,Yan Yin,Jilong Wang,Yongping Zeng
Adsorption desulfurization represents an alternative technology for the effective removal of thiophenic compounds from fuels. Metal−organic frameworks have been the ideal candidates for the adsorptive desulfurization of fuel due to the high surface areas. Pristine UiO-66 is thought to be appropriate for the removal of small thiophenic compounds. This work developed a new type of hierarchical-pore (micro and mesopores) UiO-66 with a higher specific surface area and porosity for the removal of larger adsorbates using MOF-5 as the template. To enhance adsorption desulfurization performance, the Ag + -exchanged hierarchical-pore UiO-66 (HP-UiO-66-SO 3 Ag) with π-complexation was synthesized by the ion-exchange method. The HP-UiO-66-SO 3 Ag samples were characterized by FTIR, XRD, SEM, TEM, and N 2 adsorption–desorption isotherms. Compared with the original UiO-66, the HP-UiO-66-SO 3 Ag has a higher specific surface area, pore volume, and pore size. The static adsorption experiments showed that HP-UiO-66-SO 3 Ag had a high adsorption capacity for thiophene and benzothiophene . Moreover, the HP-UiO-66-SO 3 Ag sample still exhibits high adsorptive performance in the presence of toluene. The regeneration results show that about 90% of the initial adsorption capacity of HP-UiO-66-SO 3 Ag can be regenerated after four cycles.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Qunfeng Kuang,Kun Liu,Qikun Wang,Qibing Chang
Biochar is used as adsorption material for transition metal ions based on its special high surface area. However, the ion adsorption capacity is limited by the inability through the increasing of specific surface area. Three-dimensional hierarchical pore biochar (ASPB) is prepared by pre-carbonization and KOH activation using soybean protein with gelation properties to construct a three-dimensional framework structure of biomass. The saturation level of Cr(VI) adsorption in 250 mg·L −1 Cr(VI) solution is 489.66 mg·g −1 , which is attributed to the ASPB's vast 2788 m 2 ·g −1 surface area and three-dimensional hierarchical pore structure, with pore structure data indicating an empty volume of 1.65 cm 3 ·g −1 and a 2.386 nm size average pore size. The Cr(VI) adsorption level is higher than the calculated saturated capacity according to Langmuir equation based on the specific surface area. The extra adsorption performance is contributed to the transport channels provided by the three-dimensional framework structure, the large and abundant ion riveting sites provided by micro-mesopores, and the redox and complexation of surface-active groups. The saturated adsorption capacity can keep 86.6 % after three adsorption–desorption cycles.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Xinling Yu,Nian Li,Shudong Zhang,Cui Liu,Liqing Chen,Shuai Han,Yanping Song,Mingyong Han,Zhenyang Wang
Constructing 3D graphene frameworks with ultra-thickness and rich ion transport paths is of great significance for the practical application of graphene supercapacitors . Herein, 3D porous graphene frameworks, with thickness up to 320 μm, are directly grown by laser induction on the synthesized polyimide by optimizing the thermal sensitivity of polyimide to increase laser penetration depth. Simultaneously, hierarchical pores are obtained due to fast liberation of gaseous products during laser radiation, which facilitates fast ion transport. Coupled with its conductive interconnection network, the as-prepared 3D graphene delivers a high specific capacitance of 132.2 mF cm −2 at 0.5 mA cm −2 , which is nearly one order of magnitude larger than that of most reported laser induced graphene electrodes. Pseudocapacitive polypyrrole is further introduced into the graphene frameworks to prepare composite electrodes, which show specific capacitances as high as 2412.2 mF cm −2 at 0.5 mA cm −2 . Accordingly, flexible solid-state micro-supercapacitors are constructed, with a high energy density of 134.4 μW h cm −2 at a power density of 325 μW cm −2 . Furthermore, 95.6% of initial capacitance is retained after 10,000 cycles, indicating superior cycling stability. These results suggest that the ultra-thick hierarchical porous graphene frameworks have promising prospects for high-performance flexible micro-supercapacitors.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）