Crystals
·
2021
·Vol. 11
·期 10
·1247
·
IF 2.589
Changsheng Zhang,Kai Fan,Ge Ma,Chi Lei,Wei Xu,Jie Jiang,Bing Sun,Hongxing Zhang,Yunfeng Zhu,Song Wen
Hierarchical zeolites attract people’s attention due to their enhanced mass transfer properties in catalytic reactions. The research over obtaining these zeolites in green and efficient methods is of great significance for the current post-treatments and templating strategies tend to be costly for hierarchical zeolite synthesis. In this research, nanosized mesoporous ZSM-5 (SN-ZSM-5) zeolites have been synthesized without the addition of mesoscale templates under highly concentrated conditions. The physicochemical characteristics were systematically investigated by XRD, SEM, N2 sorption, TEM, and NMR. The SEM images showed ZSM-5 crystals with sizes between 50–110 nm were obtained. N2sorption and high-resolution TEM images gave direct evidence for the hierarchical structure of SN-ZSM-5. The forming mechanism for the hierarchical structure was proposed that the etching effect of the highly alkaline environment for the starting gels played a critical role in the formation of hierarchical structure. Catalytic tests in methanol-to-olefins (MTO) showed the SN-ZSM-5 performed a longer catalyst lifetime and higher propylene selectivity than the conventional ZSM-5 zeolites (C-ZSM-5) obtained from a traditional hydrothermal method. The features of hierarchical structure in the SN-ZSM-5 crystals and the sustainability for synthesis method could show a promising choice for wide applications of these SN-ZSM-5 zeolites in the future.Keywords:ZSM-5 zeolite;efficient synthesis;hierarchical;nano crystals
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
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2024
·Vol. 40
·期 4
·704-711
·
IF 3.1
Zheng Mingdan,Chen Ya,Liu Zhan,Lyu Jiamin,Ye Bo,Sun Ming-Hui,Chen Li-Hua,Su Bao-Lian
Hollow zeolite microspheres have recently attracted much attention for their applications in catalysis, microreactors and biomedicine. Herein, we present hierarchically structured zeolite ZSM-5 microspheres with unique, abundant macropores that allow more efficient use for catalysis. The hierarchically macroporous zeolite ZSM-5 microspheres are synthesized under the assistance of water/oil emulsions and using polystyrene nanospheres as templates. The zeolite microsphere is assembled by uniform hollow zeolite nanospheres. Their large inner cavities and thin zeolite shells lead to smaller diffusion channel and higher improved accessibility to active sites, contributing to high catalytic performance in the catalytic conversion of benzyl alcohol in mesitylene. Such novel zeolite microspheres with impressive performance will be applied to numerous other industrial catalytic reactions.
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
Frontiers in Chemistry
·
2019
·
IF 3.782
Li Renna,Chong Shijia,Altaf Naveed,Gao Yanshan,Louis Benoit,Wang Qiang
In this research, we investigated the hydrophobicity and dynamic adsorption-desorption behaviors of volatile organic compounds (VOCs) by applying different optimized coating dosage (25, 50, and 75%) on designed novel ZSM-5/MCM-41 and ZSM-5/Silicalite-1 hierarchical composites. The relatively large specific surface area and pore volume of adsorbents ZSM-5/MCM-41 and ZSM-5/Silicalite-1 composites with excellent stability were affirmed by ex-situ XRD, FTIR, BET, SEM, and water contact angle analyses. Regarding, toluene adsorption-desorption investigation, ZSM-5/MCM-41 composite lead a longer stable toluene breakthrough time no matter under dry or 50% humid conditions. However, under different loading dosage condition, the breakthrough time of 75% coating ratio was the longest, which was 1.6 times as long as that of pure ZSM-5 under wet adsorption. Meanwhile, the complete elimination of toluene for ZSM-5/MCM-41-75% was done by largest desorption peak area and the lowest desorption temperature of 101.9°C, while, the largest contact angle of ZSM-5/MCM-41-75% was 17.0° higher than pure ZSM-5 zeolite. Therefore, we believe that the present hydrophobic sorbent will provide new insight with great research potential for removing low concentration of VOCs at industrial scale.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
FUEL
·
2020
·
IF 5.578
Chenyao Bi,Xu Wang,Qing You,Baoyu Liu,Zhuo Li,Jianbo Zhang,Qingqing Hao,Ming Sun,Huiyong Chen,Xiaoxun Ma
Five MFI-type zeolite catalysts, which were aluminosilicate ZSM-5 (Z5), gallium-substituted silicalite-1 (Ga-S1), mesoporous ZSM-5 (MZ5), gallium-substituted mesoporous silicalite-1 (Ga-MS1) and gallium-substituted mesoporous ZSM-5 (Ga-MZ5), were hydrothermally synthesized with combined using of TPAOH and TPOAC as micropore and mesopore structure-directing agents respectively, followed by the application in the catalytic upgrading of volatiles from low-rank coal fast pyrolysis. The obtained results indicated that significant improvements with the yield of high value-added products of BTEXN (benzene, toluene, ethylbenzene, xylene and naphthalene) increased from 5.4 mg.g −1 to 11.9–26.4 mg.g −1 , as well as the content of light fractions (<300 °C) in coal tars increased from 51% to 65–88% were realized by using the representative MFI-type zeolite catalysts in contrast to non-catalyst pyrolysis. Moreover, the possible mechanism for catalytic upgrading over the best-performing catalyst of gallium-substituted mesoporous ZSM-5 (Ga-MZ5) with the highest yield of aromatics and effective reduction of phenols was proposed on the basis of systematic comparison of structural features and catalytic performances of various MFI-type zeolite catalysts and fundamental study of the synergetic effects dominated by acidity, ratio of Brønsted/Lewis acid sites, intra-/extra-framework gallium species and hierarchical meso-/microporosity.
研究领域:
能源化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2021
·Vol. 13
·期 16
·3601-3610
·
IF 5.686
Bing Xu,Minghui Tan,Xuemei Wu,Hailun Geng,Shengying Zhao,Jie Yao,Qingxiang Ma,Guohui Yang,Noritatsu Tsubaki,Yisheng Tan
Graphical Catalytic propane aromatization : Post-introducing Cr species to Ga/Z5 catalyst had the maximum dehydrogenated active Cr 3+ species. Propane was effectively converted, and more light alkenes from propane dehydrogenation were converted into BTX on 2Cr/GaZ5 catalyst. Active Cr 3+ species and strong interaction between Ga species and ZSM-5 zeolite on 2Cr/GaZ5 catalyst accelerated the dehydrogenation step in propane aromatization. Accelerating propane dehydrogenation in propane aromatization is vital because it is the first and rate control step. In this study, we introduced Cr to Ga/ZSM-5 by tuning its impregnation sequence and amount, which was expected to accelerate the dehydrogenation step and improve aromatization performance. The impregnation sequence of Cr on catalyst not only affected the interaction between Ga and ZSM-5, but also tuned the amount of dehydrogenation active species Cr 3+ . Due to the plenty of Cr 3+ species and strong interaction between Ga species and ZSM-5, 2Cr/GaZ5 catalyst accelerated the dehydrogenation step and improved the aromatization process. More light hydrocarbons were preferred to be produced and were further converted into BTX on 2Cr/GaZ5 catalyst. Excessive Cr on catalyst caused the formation of Cr 2 O 3 particles with worse dispersion. The aggregated Cr 2 O 3 decreased the strong acidity of catalyst, which could not further promote propane conversion and decreased the aromatization ability of catalyst.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Dezhu Zhang,Su Fan,Kenan Xu,Haotian Liu,Nana Chang,Yijie Wang,Yixing Wang,Kang Huang,Zhi Xu
Vanadium flow battery (VFB) shows great potential in balancing the volatility of renewable energy. In this work, we investigated, for the first time, the various properties of crystalline ZSM-5 membranes prepared through the organic template-free gel strategy in VFB. The subnano windows (∼0.55 nm) of ZSM-5 zeolite provided selective transport paths for protons (∼0.27 nm) and blocked the vanadium (>0.6 nm) migration through pore repulsion effect. The zeolite membranes exhibited a very low vanadium penetration rate (0.05 mmol L–1 h–1), achieving a Coulombic efficiency (CE) of 96.1%, a voltage efficiency of 78.3%, and an energy efficiency of 75.3% at the current density of 40 mA cm–2. Notably, ZSM-5 prepared using the template-free strategy eliminates the need for a high-temperature calcination step, and the membrane has a lower defect density and exhibits a higher CE. The self-discharge time of the ZSM-5 zeolite membrane increased up to 78 h. Furthermore, the charge–discharge performance kept stable more than 300 cycles at 60 mA cm–2.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2025
·
IF 2.7
Feng Ye,Shuanshi Fan,Yanhong Wang,Xuemei Lang,Yihui Lv,Weibo Chen,Gang Li
The facile synthesis of hierarchical ZSM-5 zeolites without mesoporogens is highly desirable for industrial applications. In this study, hierarchical ZSM-5 zeolites with abundant mesopores and a nearly single-crystalline structure were rapidly synthesized in a mesoporogen-free system. Under conventional heating, the synthesis time was significantly reduced to just 15 min, significantly improving production efficiency. The key to this ultrafast process was the use of a tubular reactor, combined with the strategic selection of silicon and aluminum sources.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2015
·
IF 3.893
Jing Xing,Liang Song,Cong Zhang,Mingdong Zhou,Li Yue,Xuebing Li
Upgrading of lignin derived bio-oil is a very promising way to relieve humankind's dependence on traditional fossil fuels. Eugenol, a model compound for lignin monomers with a methoxyl group and a hydroxyl group, was hydrodeoxygenated in aqueous phase with Pd/C as hydrogenation catalyst and ZSM-5 zeolite as hydrolysis and dehydration catalysts. The bulky lignin monomers had difficulty in accessing the acid sites of the micropores of ZSM-5 zeolite, thus we introduced mesopores via alkaline treatment under various conditions. Alkali-treated ZSM-5 zeolites showed higher conversion and hydrocarbon selectivity compared to the parent ZSM-5 zeolite. When ZSM-5 zeolite was treated at 338 K, the conversion and the hydrocarbon selectivity increased by 21% and 24%, respectively. In addition, much more weak acid sites of ZSM-5 zeolites after alkaline treatment also promoted the hydrolysis and dehydration process.
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
SURFACE REVIEW AND LETTERS
·
2019
·
IF 0.748
DONGJING LIU,WEIGUO ZHOU,JIANG WU
Perovskite LaFeO 3 /ZSM-5 is synthesized via citrate route for H 2 S removal at high temperatures. It shows good thermal stability after heat treatment at 500–700 ∘ C with respect to slight changes in crystallographic phase and textural property. It presents the optimal desulfurization performance at 600 ∘ C with sulfur capacity of 1017 μ mol S/g and products of S, LaS 2 , and Fe 7 S 8 . Sulfidation at 500 ∘ C yields the same products as sulfidation at 600 ∘ C but displays the lowest sulfur capacity of 408 μ mol S/g. Sulfidation at 700 ∘ C produces La 2 O 2 S, Fe 3 S 4 , and unreacted LaFeO 3 . The activation energy of the sulfidation reaction over LaFeO 3 /ZSM-5 is 109.6 kJ/mol.
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
ChemistrySelect
·
2024
·Vol. 9
·期 21
·e202304264
·
IF 1.9
Haoyu Liu,Guoliang Zhang,Hong Yuan
Graphical A series of hierarchical ZSM-5 nanocrystalline aggregates (HNZ-5) was synthesized for the catalytic cracking of model waste cooking oil model compound (WCOMC) to produce light olefins. A series of hierarchical ZSM-5 nanocrystalline aggregates (HNZ-5) was synthesized using a hydrothermal method with tetrapropylammonium hydroxide as a structural guide. The HNZ-5 samples having different Si/Al molar ratios all showed suitable hierarchical architectures and the maximum surface area was found to be 329 m 2 /g. The SEM image displayed the width of the individual crystal particles was ~100 nm, and its nanocrystalline clusters generated intercrystalline pores. Temperature-programmed desorption with NH 3 indicated that the total acidity of this material increased with increases in the Al 3+ content to a maximum of 0.47 mmol/g at a Si/Al ratio of 15. In addition, 27 Al magic angle spinning nuclear magnetic resonance spectra showed that the acid sites were associated with tetrahedral and octahedral Al sites. This HNZ-5 was applied to the catalytic cracking of waste cooking oil model compound and gave a light olefin yield as high as 43.9 % at 550 °C. Extending the reaction time to 6000 min provided a yield of light olefins in excess of 30 %, which was higher than that achieved using traditional ZSM-5. These data confirmed that the hierarchical pore structure of HNZ-5 resulting from the self-assembly of nanocrystals, together with exposed acidic sites, promoted the catalytic conversion of large molecules.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Yan Wang,Sai Li,Yanchao Liu,Jiajun Zheng,Xiaobo Sun,Yanze Du,Zhiping Liu,Bo Qin,Wenlin Li,Guangshuai Wang,Meng Pan,Ruifeng Li
Hierarchical ZSM-5 with loose nanocrystallites was synthesized by a traditional hydrothermal procedure. Factors controlling the formation of hierarchical zeolite were investigated in detail. Despite having comparable acid properties, the increased external surfaces offer the hierarchical ZSM-5n an excellent catalytic performance. After reaction for 414 h, the hierarchical ZSM-5n catalyst still keeps a 88.5% conversion of isopropylbenzene, while the ZSM-5μ and ZSM-5m catalysts only show 37.5% (25.8 h), 28.2% (11 h) conversions, respectively; the initial conversion of n-octane over ZSM-5n is 94.3 wt %, obviously higher than 82.8 wt % on ZSM-5μ, the half-life period related to the catalytic activity on ZSM-5n and ZSM-5μ are 271 h, and 22 h, respectively. The prolonged catalysis life for hierarchical ZSM-5n during the catalytic cracking of n-octane is ascribed to the shortened diffusion path length and an “excretory system”, carbon nanotubes (CNTs) self-generating during the cracking processing. The shortened microporous channels attribute to weakening adsorption energy barrier and promoting the coke precursors rapid diffusing toward the pore windows. Moreover, the autogenetic CNTs help the carbon precursors escaping from the pore windows and keep them far away from the zeolite crystals in the catalysts. That avoids the carbon deposit in the micropores as well as in the pore windows and on the external surface of the catalyst.
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
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Guopei Zhang,Cong Wang,Xiaoyang Zhang,Yong Dong,Zhaomin Li,Leteng Lin
Effective elemental mercury (Hg 0 ) removal from syngas is essential for industrial mercury control. This study synthesized LaMeO x /ZSM-5 (Me = Zn, Cu, and Fe) sorbents via the sol–gel method and evaluated their Hg⁰ removal performance for simulated syngas at 50–250 °C. The physico-chemical properties of samples were characterized by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), H 2 temperature-programmed reduction (H 2 -TPR) and X-ray photoelectron spectroscopy (XPS). La 2 CuO 4 /ZSM-5 demonstrated superior efficiency (≥95 %) at 50–200 °C under simulated syngas, attributed to its porous structure and abundant surface-active oxygen. H 2 S significantly enhanced Hg 0 removal by forming active sulfur species, while H 2 , CO, and H 2 O inhibited performance due to competition for active sites. The inhibitory effects were mitigated by adding 500 ppm H 2 S. XPS and TPD analyses revealed HgS (cinnabar) as the dominant mercury species, with Cu 2+ ions and active oxygen critical for Hg 0 capture. Stability tests confirmed excellent reusability, with over 88 % efficiency maintained after 10 adsorption-regeneration cycles. La 2 CuO 4 /ZSM-5 emerges as a promising sorbent for Hg 0 removal, offering high efficiency, stability, and resistance to syngas components, making it suitable for industrial applications.
研究领域:
环境科学
·
材料科学
✓ 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）