Nano Research
·
2021
·Vol. 14
·期 11
·4304-4313
·
IF 8.897
Zhai Yi,Wang Fumin,Zhang Xubin,Lv Guojun,Wu Yuzhou,Jiang Tao,Zhang Qing,Li Mengyue,Li Mengyao,Liu Yongkui
How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe 2 O 3 nanoparticles (2.5 nm) with higher yield (85.2%) by mother liquid than traditional dissolution-recrystallization for the first time, which was achieved by precisely regulating the number and distribution of defects in zeolite and cleverly utilizing the TPAOH and nuclei in mother liquor. The effects of synthetic temperature, synthetic period and addition amount of parent zeolite on the formation of hollow zeolite have been investigated and the effect of synthetic conditions on the defects in parent zeolite has been also firstly quantified. The corresponding formation mechanism has been proposed. The abundant inner defects provided by the zeolite synthesized at 130 °C for 1 day and large amount of TPAOH remaining in mother liquid are conducive to the formation of hollow zeolite. Meanwhile, both parent zeolite and nuclei (4-, 5-member rings and structure units) in mother liquid obtained at 130 °C play the crucial roles in enhancing the zeolite yield. Notably, Fe 2 O 3 nanoparticles could decompose into small fragments by the interaction with nuclei in mother liquid. Partial ultra-small Fe 2 O 3 nanoparticles would be encapsulated in cavity and the rest could be inserted in the zeolite framework, which is significantly different from the conventional dissolution-recrystallization mechanism. The obtained encapsulated catalyst shows the superior catalytic performance and stability in phenol and tetracycline degradation reactions.
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Jiali Yu,Jiahui Li,Haipeng Zhu,Gongping Liu,Wanqin Jin
Membrane technology can reduce the energy consumption of alcohol/water separation process, while the membrane performance still needs to be improved. This study reports a fluoride-mediated hydrophobic zeolite incorporated polydimethylsiloxane (PDMS) membrane for highly selective separating ethanol from aqueous solution. A fluoride-assisted synthesis strategy was proposed to achieve synergistic control over the morphology and surface chemical properties of siliceous zeolites. Comprehensive characterizations revealed that fluoride-mediated MFI zeolite (F-MFI) possessed significantly lower silanol density and superior hydrophobicity compared to conventional hydroxide-synthesized MFI zeolite (Si-MFI), thereby improving the selective permeation of ethanol over water. The optimal F-MFI nanoplates (∼150 nm thickness) with high crystallinity were uniformly incorporated into the PDMS membrane, achieving outstanding performance for separating 5 wt% ethanol/water mixture at 40 °C (total flux of 1409 g m −2 h −1 and a separation factor of 19.7—approximately twice that of the pure PDMS membrane). This work provides a high-performance ethanol-selective membrane, and also demonstrates the importance of synthesis condition on the morphology and functionality of filler and the performance of resulting mixed-matrix membrane.
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高影响因子
CRYSTAL GROWTH & DESIGN
·
2026
·
IF 3.6
Yihao Wang,Kaiwei Wang,Fumin Wang,Yi Zhai,Xuyang Zou,Yan Chen,Hao Ruan,Jiaxing Zhang,Xubin Zhang
Vanadium-containing MFI zeolites have attracted increasing attention as heteroatom zeolite catalysts; however, precise regulation of vanadium speciation within the framework remains challenging. Herein, N-methylformamide (NMF) was introduced as an additive to assist the hydrothermal synthesis of vanadium-MFI zeolite enriched with framework-associated V4+ = O(OSi)2(OH) species. The resulting catalyst exhibits high catalytic activity in oxidative desulfurization (ODS), achieving 91.63% conversion of dibenzothiophene (DBT) within 20 min and nearly complete conversion within 45 min, together with a high turnover frequency of 117.1 h–1. Spectroscopic analysis suggests that V4+═O(OSi)2(OH) is a highly active vanadium species for the ODS reaction. By dynamically tracking the evolution of vanadium species during crystallization, the possible role of NMF in regulating vanadium coordination and framework incorporation was elucidated. The results reveal that both NMF concentration and crystallization time are critical parameters governing the formation of V4+═O(OSi)2(OH). Comparative studies using different amide additives, combined with catalytic performance and density functional theory calculations, further support that the coordination ability of amides toward V4+═O determines vanadium speciation and catalytic activity. This work provides mechanistic insight into amide-assisted regulation of heteroatom environments in zeolite frameworks and offers a rational strategy for designing highly active oxidation desulfurization catalysts.
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高影响因子
ACS Catalysis
·
2022
·
IF 13.7
Bin Gao,Bin Qiu,Mingji Zheng,Zhankai Liu,Wen-Duo Lu,Qiang Wang,Jun Xu,Feng Deng,An-Hui Lu
Boron-containing zeolites have been demonstrated as active catalysts for oxidative dehydrogenation of propane (ODHP) to propene. The challenge is that the origin of the boron active sites remains an unsolved issue. In this study, self-pillared boron-containing MFI zeolite nanosheets with an ultrathin b-axis were synthesized, which exhibited low-temperature activity and stability in the ODHP process. A combination of in situ diffuse reflectance infrared Fourier transform, two-dimensional 11B multiple-quantum MAS NMR, and 11B{1H} dipolar-heteronuclear multiple-quantum correlation NMR measurements revealed that the MFI zeolite nanosheets with the characteristics of a high specific surface area and abundant Si–OH groups allowed dynamic self-dispersion of highly mobile boron clusters through condensation with surrounding Si–OH groups. The increased number of stable and dispersed oligomeric boron species was responsible for the enhanced catalytic performance and stability in the ODHP process. The catalysts were active at a temperature as low as 390 °C. Upon raising the temperature to 430 °C, a propane conversion of 14.1% could be achieved together with a selectivity of 80.1% toward all olefins.
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高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Linjie Guan,Chengming Huang,Dingmei Han,Linhua Zhu,Yi Mei,Dedong He,Yun Zu
Three zeolites ZSM-5, ZSM-35 and ZSM-22 are applied in n -butane cracking to reveal the influence of regional differences in Brønsted acid sites on reaction pathways. The Brønsted acid sites located in the channels of ZSM-5 exhibit a higher catalytic activity and yields to light olefins (especially the ethylene), which can be attributed to more relative contribution of bimolecular pathway. In comparison, more Brønsted acid sites are situated on the external surface or micropore mouths of ZSM-35 and ZSM-22, which are beneficial to propylene production. Note-worthily, almost no propane production on the two zeolites implies the predomination of monomolecular pathway. In situ FTIR technique further discloses that the difference in the reaction pathways is tailored by adsorption configurations of n -butane at two types of Brønsted acid sites. Under comparable conditions, the ZSM-5 performs a relatively good catalytic stability through bimolecular pathway. Furthermore, the correlation between deactivation rate and light olefins reveals that the enhancement of propylene selectivity accelerates the deactivation of ZSM-35 and ZSM-22. While, promotion on the ethylene selectivity is a significant inducement for the deactivation of ZSM-5.
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高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Meng Xu,Xiaoling Liu,Zhuo Xiong,Yue Wu,Zhen Meng,Yu Zhou,Jun Wang
Furfural is an abundant biomass-derived building block that can be converted into furan-based N-containing compounds through direct reductive amination by using dihydrogen (H 2 ). Nonetheless, the synthesis of furan-based tertiary amines is highly limited via this route. Herein, we reported the straightforward synthesis of MFI zeolite encapsulated Pt nanoparticles and finely modulated the surface electronic state by facilely controlling the reduction process. The constructed catalyst Pt@Z5 effectively catalyzed the amination of furfural with diethylamine for the synthesis of N-ethyl-N-(furan-2-ylmethyl)ethanamine, affording the high yield (>95 %), large turnover number (TON) of 2058, turnover frequency (TOF) of 1029 h −1 , and stable recyclability. Systematic investigations comprising in-situ Fourier transform infrared spectroscopy (FTIR) spectra and kinetic isotope effect (KIE) unraveled that the mild reduction condition allowed the catalyst with a superior affinity towards H atom and beneficial furfural adsorption behavior, accelerating the H 2 activation in the rate-determining step for the conversion of furfural into furan-based amine.
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高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 19
·5879-5890
·
IF 6.177
Dengfeng Dai,Chao Feng,Minmin Wang,Qingzhou Du,Dandan Liu,Yuan Pan,Yunqi Liu
Biomass-based chemicals as a renewable alternative to petroleum-based chemicals are of great significance. The conversion of biomass-based furfuryl alcohol to pentanediol, including 1,5-pentanediol and 1,2-pentanediol, is explored over a series of bifunctional Cu/MFI catalysts in a continuous-flow reactor. These catalysts are synthesized by supporting copper nanoparticles on MFI zeolites with varying molar ratios of SiO2/Al2O3. Among them, the Z60-10Cu catalyst containing balanced Cu0–Cu+ and Brønsted acid sites exhibits excellent performance, and a high furfuryl alcohol conversion of 99.5% and selectivity of 85.2% for 1,5-pentanediol (69.2%) and 1,2-pentanediol (16.0%) could be achieved (hydrogen pressure: 2.5 MPa) at 160 °C. The experimental results and the results obtained using the DFT technique revealed that the high catalytic activity realized during the processes of ring-opening and hydrogenation could be attributed to the synergistic effect between the Cu species and Brønsted acid sites. The Brønsted acid sites on the Si(OH)Al groups significantly affect the ring-opening process of furfuryl alcohol. The methoxy group on furfuryl alcohol adsorbs on the Cu+ sites, and the hydrogenation saturation of the ring-opening intermediate is realized under the influence of the activated hydrogen units on the Cu0 sites. The results reported herein could help promote the continuous production of high value-added pentanediol from biomass-based raw materials in the presence of non-noble metal catalysts. An economical and feasible path for the transformation of biomass resources into high value-added fine chemicals could also be developed.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Peng Zhang,Fan Yang,Xuedong Zhu,Weizhong Zheng
In this work, a kind of ZSM-5 zeolite with one-dimensional fins growing along the [010] direction has been successfully synthesized utilizing both tetrapropylammonium hydroxide (TPAOH) and tetramethylammonium hydroxide (TMAOH) as co-templates. With the aid of molecular dynamic simulations and a series of experimental evidences, the formation mechanism of the one-dimensional feature is determined to arise from the synergic effects between TPA + and TMA + . Two TPA + and three TMA + would co-exist in a unit MFI cell at a certain crystallization period depending on the composition of zeolite and precursor, and this configuration ensures a minimum stabilization energy required for the growth along [010] direction. Investigations manifest these needle-like fins with diameters of ca. 60 nm could function as pseudo nano crystals and introduce additional pores ranging from 10 to 90 nm, which effectively promotes the diffusion capability and substantially improves the catalytic performance in propane aromatization.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Jingshuang Zhang,He Ding,Yixiao Zhang,Chuan Yu,Peng Bai,Xianghai Guo
Hierarchical aluminosilicate zeolites were simply synthesized by a temperature-gradient strategy using conventional CTAB as single structure directing agent. The as-synthesized zeolites were composed of an ordered two-dimensional hexagonal mesopores and crystallized MFI structure. Catalytic performance of the hierarchical aluminosilicate zeolites were explored by the Claisen-Schmidt condensation of bulky reactants (benzaldehyde and 2′-hydroxyacetophenone). The reaction results showed that the hierarchical zeolites exhibit outstanding catalytic performance with a conversion as high as 73%, which may be attributed to the combined advantage of framework acidity of zeolite and the significantly improved large molecule diffussion in mesoporosity. The higher hydrothermal stability and catalytic stability than those of MCM-41 samples were proved, which were ascribed to the presence of crystallized MFI structure.
研究领域:
化学
·
催化
·
材料科学
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高影响因子
ACS Catalysis
·
2018
·
IF 11.384
Yuchao Chai,Sihang Liu,Zhi-Jian Zhao,Jinlong Gong,Weili Dai,Guangjun Wu,Naijia Guan,Landong Li
Metal nanoparticles encapsulated in zeolite have been recently developed as a special type of catalyst that shows significant advantages in activity, shape-selectivity, and stability over conventional supported catalysts. The selectivity modulation of encapsulated nanoparticle catalysis by the zeolite microenvironment is theoretically possible but not addressed yet. Here, we report the in situ encapsulation of sub-nanometric palladium species within MFI-type zeolites, which exhibit high activity and good stability in the hydroconversion of furfural as a model reaction of biomass upgrading. Remarkably, different products, e.g., furan, furfural alcohol, and 1,5-pentanediol, from furfural hydroconversion can be obtained when silicalite-1, Na-ZSM-5, and H-ZSM-5 are employed as hosts of palladium nanoparticles, respectively. Density functional theory calculations and spectroscopy investigations reveal that both the adsorption of furfural and the activation of hydrogen are significantly affected by the zeolite microenvironment, leading to different reaction pathways. Our work presents an elegant example of catalytic selectivity modulation of encapsulated metal nanoparticles by tuning the zeolite microenvironment.
研究领域:
催化
·
材料科学
·
化学工程
·
纳米技术
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高影响因子
FOOD RESEARCH INTERNATIONAL
·
2024
·
IF 7
Yehua Liu,Hongying Li,Mingming Li,Linggao Liu,Kuan Lu,Shenghui Bi,Mixin Zhou,Li Chen,Lisha Lan,Minping Wei,Ying Zhou,Qiujin Zhu
This study explored the effect of electrical stimulation (ES) and Pediococcus pentosaceus LL-07 ( P. pentosaceus LL-07) and Staphylococcus simulans QB7 ( S. simulans QB7) on the quality and microbial community of loin ham during the ripening. After the ES and starter culture treatments, the Aw and pH were decreased. Surface hydrophobicity, myogenic fiber fragmentation index (MFI), TCA-soluble peptide, amino nitrogen and free amino acids (FAAs) were also significantly higher than the control group (CK) ( P < 0.05). This increase was more significant in the E-S group (electrical stimulation followed by inoculation with P. pentosaceus LL-07 and S. simulans QB7) than the rest of the experimental group (E、S、S-E group). Furthermore, the CK and E-S groups were subjected to a bacterial community comparison experiment. The microbial diversity of these two groups was increased. Pediococcus spp. and Staphylococcus spp. became the dominant bacteria in E-S groups during the ripening. Correlation analyses show a strong correlation between protein hydrolysis, microorganisms and FAAs. In conclusion, the combination of ES and starter culture could promote protein hydrolysis, the accumulation of FAAS, and improves the bacterial community of loin ham.
研究领域:
食品科学
·
微生物学
·
生物化学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）