Journal of Water Process Engineering
·
2019
·
IF 3.173
Senlin Ma,Xingtao Zuo,Juan Xiong,Cong Ma,Zhongbing Chen
An ozonation process combined with hydrophobic adsorbent high silica ZSM-5 (HSZSM-5) was designed to enhance sulfamethoxazole (SMX) removal and reduce the ozone consumption. The promoted effect of HSZSM-5 on SMX removal was investigated in terms of SMX removal and TOC removal efficiency as well as the ozone consumption. The impacts of pH and CO 3 2− /HCO 3 - were also analyzed. The presence of HSZSM-5 helped to increase the SMX degradation and TOC removal efficiency and their kinetics rate constants. HSZSM-5 adsorption behaviors for SMX and its degradation intermediates were responsible for the findings. Direct ozone oxidation was the main mechanism of SMX removal as HZSM-5 could not contribute to producing H 2 O 2 and •OH. Much higher CO 3 2− /HCO 3 - concentration (≥10 mM) and pH value (>7) were in favor of SMX degradation. HSZSM-5 had a positive contribution to SMX removal. The mass ratio of ozone consumption to the removed SMX reduced to 0.63 g O 3 /g SMX. This system of introducing high silica zeolite in the ozonation/adsorption process is an environmentally and economically sound technology to removal micropollutants.
研究领域:
环境科学
·
水处理技术
✓ 已验证
DOI
高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 43
·e202202460
·
IF 2.307
Guohao Xu,Jiale Zhu,Xuedong Zhu
Graphical Compared with the microporous system of MoO 3 /ZSM-5 synthesized by the the physically-blended method, the micro-mesoporous system of ZSM-5@MoO 3 with a core-shell reaction pathway of Mo-acid sites tandem could accelerate the rate of the mass-transfer, promoting aromatization reaction. A novel core-shell ZSM-5@MoO 3 catalyst was successfully synthesized by the hydrothermal coating strategy, and its physicochemical properties and catalytic properties in methane aromatization were investigated using a physically-blended ZSM-5/MoO 3 catalyst as a comparison. Multitechniques including XRD, SEM, TEM, EDS, N 2 adsorption, ICP, IR and IG were employed to investigate the characteristics of methane aromatization reaction and the deactivation of carbon deposits. At the reaction temperature of 700 °C and a space velocity of 2400 mL g −1 h −1 , methane conversion and aromatics selectivity of the core-shell ZSM-5@MoO 3 catalyst were 11.3 % and 88.1 %, respectively, which were higher than those of the physically-blended ZSM-5/MoO 3 catalyst by 3.1 % and 14.8 %, respectively. The special reaction pathway of core (ZSM-5, acid sites)-shell (MoO 3 , Mo sites) and the relatively close proximity between MoO 3 and ZSM-5 were mainly responsible for the excellent properties in the methane aromatization reaction. At the same time, the formation of the micro-mesoporous property accelerated the mass-transfer rate and inhibited the formation of carbonaceous deposition, greatly improving the stability of methane aromatization. Thanks to its core-shell structure, ZSM-5@MoO 3 catalyst showed the excellent properties in methane aromatization.
研究领域:
催化化学
·
材料科学
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Leilei Dai,Yunpu Wang,Yuhuan Liu,Roger Ruan,Dengle Duan,Yunfeng Zhao,Zhenting Yu,Lin Jiang
Catalytic fast pyrolysis (CFP) of torrefied corn cob using Ni-modified hierarchical ZSM-5 catalyst was conducted in this study. The prepared catalysts were characterized by N 2 adsorption and desorption (N 2 -BET), X-ray diffraction (XRD), and temperature-programmed desorption of NH 3 (NH 3 -TPD). NaOH solution treatment resulted in the lower peak intensities of hierarchical ZSM-5 catalyst in the XRD patterns while Ni modification improved the catalyst framework. In addition, NaOH solution treatment created some mesopores or macropores, but the incorporation of Ni reduced BET surface area and volume of micropores. Though the addition of Ni lowered the acidity of catalyst, Ni-modified hierarchical ZSM-5 catalyst led to higher yields and of aromatic hydrocarbons. What is more, hierarchical ZSM-5 catalysts significantly improved the selectivities of mono-aromatics. Kinetic analysis shows that CFP of torrefied corn cob was second-order reaction and the addition of Ni can obtain a lower activation energy compared with hierarchical ZSM-5 catalyst.
研究领域:
化学工程
·
能源科学
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产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2017
·Vol. 19
·期 47
·7088-7094
·
IF 3.474
Baoliang Peng,Houbing Zou,Lipeng He,Pingmei Wang,Zhiqiang Shi,Liangkui Zhu,Runwei Wang,Zongtao Zhang
Hierarchical zeolites are promising solid acid catalysts for industrial processes and conversions of bulky molecules because they provide fast mass transfer along with size and shape selectivity; however, their synthesis always involves either complicated post-synthetic modifications or cost-intensive templates. In this work, engineering growth defects has been developed as a new and efficient strategy for preparing hierarchical ZSM-5 zeolite with high specific surface area and abundant uniform intracrystalline mesopores. This route only involved certain energy-efficient conditions, e.g., tender crystallization and mesotemplate-free conditions. Combining tender crystallization conditions with an optimal original Si/Al ratio (150–300) in a colloid synthesis system was found to be the key to successfully engineer the growth defects. Importantly, it even exhibited higher catalytic activities for benzaldehyde–alcohol condensation reactions than mesoporous ZSM-5 zeolite prepared using mesoscale templates.
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
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Qichao Lu,Jie Li,Chen Liang,Lei Liu,Jinxiang Dong
Under the dual pressures of oil depletion and low-carbon transition, Fischer-Tropsch synthesis (FTS) technology offers a viable option for producing high value-added lower (C 2 -C 4 ) hydrocarbons from non-oil sources. However, conventional Fe-based catalysts often suffer from deactivation due to carbon deposition and sintering. Here, we report a unique Fe-ZSM-5 catalyst synthesized by doping Fe into ZSM-5, which demonstrates excellent FTS catalytic performance. During high-temperature template removal, Fe species migrated from the zeolite framework to form highly dispersed FeO x clusters (∼2 nm). Upon treatment by syngas, these FeO x clusters aggregate to form uniformly small-sized Fe 5 C 2 @C core-shell particles distributed on ZSM-5 support. The confinement effect of the inter-crystalline structure effectively prevents the sintering of Fe 5 C 2 . The smaller Fe 5 C 2 particles exhibit controlled CO dissociation, reducing the concentration of activated carbon species (C*), and the carbon shells (∼6.5 nm) limit the departure of C*, effectively suppressing carbon deposition. This unique structure enables stable catalytic activity for over 100 hours with maintained product selectivity. The Fe-ZSM-5 catalyst achieved a C 2 -C 4 hydrocarbons selectivity of 54.52 %, nearing the 56 % theoretical limit of the Anderson-Schulz-Flory (ASF) distribution. Additionally, the hydrophobic carbon shell prevents excessive oxidation of Fe 5 C 2 , reducing CO 2 selectivity by ∼56 % compared to conventional Fe/ZSM-5 catalysts, significantly enhancing atomic utilization efficiency and aligning with the principles of green development.
研究领域:
化学工程
·
材料科学
·
能源催化
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2024
·
IF 5.8
Yingna Li,Muhammad Sajjad Ahmad,Mudassir Hussain Tahir,Maryam Bashir,Arif Muhammad Khan,Rana Muhammad Irfan,Imran Riaz Malik,Boxiong Shen
This study investigates the selective production of aromatics through the co-pyrolysis of cabbage waste and plastics followed by catalytic reforming with Ni-modified ZSM-5. Co-pyrolysis significantly improves the inflection point (a parameter for determining thermal stability) to 251.3 °C from 232.7 °C. This process also enhances the relative yield of olefins and phenols , which are precursors for aromatic production to 25.46 and 17.23 respectively, up from 13.87 to 12.05. Furthermore, catalytic pyrolysis elevates the relative yield of aromatics to 53.4, as confirmed by Thermogravimetric Analysis (TGA) and Thermogravimetric-Fourier Transform Infrared Spectroscopy (TG-FTIR) analyses. GC-MS confirms the enhanced formation of valuable chemical precursors via co-pyrolysis such as phenols and olefines to 18.67 % and 22.13 % leading to a 63.81 % selective yield of aromatics in the final oil with 10Ni/ZSM-5. Ni modification of ZSM-5 is influential in decreasing PAH formation (7.26 % from 20.37 %), indicating that this two-step process is an effective method for transforming waste into high-quality bio-oil with enriched aromatic content.
研究领域:
环境科学
·
能源化学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 35
·16486-16500
·
IF 3.5
Jiao Chuyu,Jiao Qirui,Zhang Wei,Ji Zhuo,Zheng Jiajun,Dai Weijiong,Wang Yan,Pan Meng,Li Ruifeng
Introduction of mesopore system into zeolite crystals is always deemed to be an effective strategy to improve diffusion and acidic accessibility. In this work, a hierarchically structured ZSM-5 with an ultra-small intracrystalline mesopore structure was prepared by using lysine as a pore-forming agent via a hydrothermal crystallization procedure. The structured and textured properties of the as-synthesized samples were characterized by XRD, SEM, EDS, TEM, NH 3 -TPD, FT-IR and N 2 adsorption–desorption isothermals. The results showed that a purely-phased hierarchical ZSM-5 zeolite with a size of 2–6 nm mesopore can be obtained under the condition of lysine/Al 2 O 3 = 2–8. The addition of lysine in the precursor not only generated an ultra-small mesopore system, but also had a significant effect on the acidity of the synthesized sample: With the increased amount of added lysine, the acid density and acid strength of the as-prepared zeolite catalyst were gradually weakened. The effects of the introduced hierarchical pore structure and the tailored acid sites on the catalytic performance of the catalysts were investigated during methanol dehydration to hydrocarbons reaction. The introduced hierarchical pores and the weakened strong acids significantly improved the stability of the catalyst. Meanwhile, the reduced acid density strongly inhibited hydrogen transfer of light olefins intermediate and then increased the selectivity toward light olefins on the hierarchical zeolite catalysts. Graphical abstract To overcome phase separation resulted from brittle combining forces between template and zeolite precursor, lysine, which is easily soluble in water and has a stable structure in the temperature range of ZSM-5 synthesis, served as a mesoporous template, and then, a hierarchical ZSM-5 zeolite was prepared in a hydrothermal method.
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
FUEL
·
2025
·
IF 7.5
Qicheng Li,Xihu Zhao,Xiaobo Song,Juan Dong,Zhitong Zhao,Pan Hao,Qi Shi,Xuekuan Li
Benzene alkylation with syngas is attractive for alkylbenzene production, which use metals/metal oxides combining H-ZSM-5 zeolites as the catalyst. Herein, the H-ZSM-5 zeolites with three different morphologies—spindle-, flake-, and nano-sized—were synthesized. Subsequently, crystal structural, textural and acidic properties of three H-ZSM-5 zeolites and their corresponding bifunctional catalysts were characterized and the catalytic reaction activity and stability of the benzene alkylation with syngas were investigated. The bifunctional catalyst derived from nano-sized zeolites demonstrates an initial benzene conversion rate of 46.7% and reduces by 71.78% after 51 h of continuous operation, owing to abundant acid sites, large surface area and mesopores diameters, and balanced acidity to promote reactant and product diffusion. The spindle-shaped zeolite catalyst delivers the highest initial benzene conversion rate (53.77%) due to abundant acid sites. However, the benzene conversion rate drops to 12.12% of the initial value after 39 h due to limited micropore volume and relatively small mesopore diameters of the catalyst. The flake-shaped zeolite catalyst exhibits the lowest initial conversion rate and the shortest lifetime (30 h) owing to the fewest accessible acid sites and the peculiar pore structure. Three cases indicate that increasing mesopore volume is conducive to improve ratio of Brønsted to Lewis acid sites (B/L), resulting in enhancement of the catalytic activity. Meanwhile, the huge micropore volume and increased mesopore diameter are positive to alleviate pore blockage and coverage of active sites due to high mass-transfer efficiency within the zeolitic channels. These textural advantages collectively contribute to a delayed catalyst deactivation process and sustained catalytic activity. This work highlights the pivotal role of the H-ZSM-5 morphology in the benzene alkylation process with syngas and facilitates the efficient development of production process for non-oil alkylbenzene.
研究领域:
催化化学
·
材料化学
·
石油化工
·
多相催化
·
纳米材料
✓ 已验证
产品关联
DOI
高影响因子
Science China-Chemistry
·
2024
·Vol. 67
·期 4
·1242-1249
·
IF 10.4
Zhang Jingjing,Deng Yongyan,Gai Dongxu,Shi Yang,Feng Xingwen,Li Peilong,An Yongtao,Zou Xiaoqin
Isotopic separation is of paramount importance for producing high-purity heavy hydrogen, yet the process remains hugely challenging. Here, we report on an Fe/ZSM-5 zeolite that was able to efficiently separate deuterium from protium via chemical quantum sieving. Structural data showed that four types of Fe species were present in Fe/ZSM-5 and oligomeric Fe–O clusters in the zeolite pores were correlated directly with gas selectivity. Gas adsorption revealed that Fe–O species served as the main adsorption sites and interacted with D 2 more strongly than with H 2 . D 2 /H 2 separation was exemplified using thermal desorption spectroscopy. D 2 /H 2 selectivity increased with Fe loading in Fe/ZSM-5 and a selectivity of 32.1 was obtained with an optimal loading of 7 wt%. The shift of desorption temperature supports the chemical affinity-based quantum sieving of D 2 over H 2 . This study demonstrates an effective strategy for enhancing D 2 /H 2 separation and the high selectivity means that Fe/ZSM-5 has strong potential in hydrogen isotope separation.
研究领域:
材料科学
·
物理化学
·
分离科学
·
催化化学
·
纳米材料
✓ 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
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Zhen-Qiang Yu,Yao-Xin Xiao,Dong Liang,Che Zhao,Zhen Huang,Gang-Qi Cheng,Rui Shan,Hao-Ran Yuan,Yong Chen
The chemical upgrade of the waste polyester coating on the surface of aluminum cans to value-added products can not only decrease the release of toxic substances, but also improve the quality of aluminum in the recycling process. In this study, different types of zeolite molecular sieve catalysts loaded with Ni, Mo and Co were synthesized, and utilized in the rapid catalytic pyrolysis of polyester coating. Among them, the Ni/ZSM-5 achieved the maximum aromatic compounds yield of 68.43 % at 600 ℃. A series of characterization results demonstrated that the embedding of transition metals (like Ni) could promote the cyclization and aromatization of products through deoxidation and dehydrogenation reactions by changing the pore structure and increasing total acid content (Brønsted and Lewis acids) of the ZSM-5 molecular sieve. Meanwhile, the thermodynamics of polyester coating during catalytic pyrolysis was studied by thermogravimetric method. The average activation energy of Ni/ZSM-5 catalytic pyrolysis of polyester coating is 238.65 kJ/mol. Furthermore, even after being reused for over 5 cycles, the catalyst can still maintain a relatively high yield of aromatic compounds (exceeding 60 %). Finally, the mechanism for aromatic compounds formation from Ni-modified ZSM-5 in-situ catalyzed polyester coating pyrolysis was proposed. This work provided useful ideas for the subsequent treatment of solid wastes.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2025
·
IF 1.9
Xudong Wang,Yanyang Wu,Tianyou Wang,Bin Wu,Kui Chen,Lijun Ji
M-cresol and p-cresol, typically produced as mixtures in industrial processes, are crucial chemical intermediates. However, their separation is challenging due to their similar structures and properties. ZSM-5 zeolite has shown potential as an adsorbent for separation, while the performance is yet to be improved. In this study, ZSM-5-F(x) was synthesized via hydrothermal method, incorporating F − ions during the synthesis process. The adsorption behaviour of m-cresol and p-cresol on ZSM-5-F(x) was investigated through static experiments, with ZSM-5-F(8) demonstrating the highest selectivity (9.01). Both ZSM-5-F(0) and ZSM-5-F(8) were characterized using XRD, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) techniques. In addition, the introduction of F − ions increased the material's electronegativity, as demonstrated by the change in zeta potential from 53.22 to −45.93 mV. Single-component adsorption of m-cresol or p-cresol on ZSM-5-F(0) and ZSM-5-F(8) respectively were investigated in detail. The adsorption of m-cresol on ZSM-5-F(8) showed a non-monotonic phenomenon with a significant decrease after 0.06 mol/L. The thermodynamic parameters including Δ G , Δ H , and Δ S were calculated accordingly. All the values |Δ G |, |Δ H |, and |Δ S | of both components on ZSM-5-F(8) were greater than those on ZSM-5-F(0), suggesting that the introduction of F − ions facilitated the adsorption. Competitive adsorption experiments on both ZSM-5-F(0) and ZSM-5-F(8) were conducted at 298.2 K. The results indicated that the selectivity α p/m on ZSM-5-F(8) increased with increasing initial concentration and laid between 13 and 14. After seven consecutive regeneration cycles, the selectivity (α p/m ) only decreased to 13. This study suggests that ZSM-5-F(8) could be a promising adsorbent for m-cresol and p-cresol in industrial applications.
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
危险品化学品经营许可证（带存储）