MATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK
·
2020
·Vol. 51
·期 9
·1295-1303
·
IF 0.744
Y. Qian,H. Zhang,L. Li,Y. Duan
In this study, ZSM-5 zeolite with hierarchical porosity structure was synthesized by hydrothermal method using Al(OH) 3 , SiO 2 extracted from coal fly ash as aluminum source and silicon source. The optimal synthesis parameters of ZSM-5 zeolite were determined via an orthogonal analysis table. The optimum synthesis conditions were: SiO 2 /Al 2 O 3 /Na 2 O/hexadecyltrimethylammonium bromide/tetrapropyl ammonium bromide/H 2 O = 1/0.08/0.25/0.05/0.17/50, and the optimum crystallization temperature and crystallization time were 160 °C and 48 h, respectively. Scanning electron microscopy showed that the synthesized ZSM-5 zeolite exhibited a spherical shape. Nitrogen adsorption-desorption and Brunauer-Emmett-Teller measurement analysis displayed that the best sample ZSM-5 molecular sieve showed a typical type IV isotherm, and the micropores and mesopores coexisted in the sample, indicating the successful preparation of ZSM-5 zeolite with hierarchical porosity structure. The crystal growth of ZSM-5 under different hydrothermal conditions follows the “S” adjustment.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2025
·
IF 2.3
Zhu Mengxuan,Li Hongqing,Wang Xin,Wang Longyang,Wang Rui,Jiang Heng,Jin Changzi
Design of efficient metal-acid bifunction catalysts is of significance for development of hydroisomerization of linear alkanes. In this study, the spatial configurational construction of Pt-ZSM-5 catalytic system was achieved by fabrication of acidic ZSM-5 zeolite and mesoporous silica core-shell composites equipped with controlled location of Pt sites, which aim to explore the effect of functional sites proximity on isomerization reactivity. A series of characterization techniques such as X-ray diffraction, transmission electronic microscopy, N 2 physical adsorption, NH 3 temperature programmed desorption, X-ray photoelectron spectroscopy and so on had confirmed that the synthesized core-shell bifunctional catalysts with different Pt location possessing similar textural, acid and metal properties. In the catalytic hydroisomerization of n -heptane, however, the catalyst with Pt sites locating at acid zeolite exhibits superior n -heptane conversion and isomerization selectivity, which indicates that proximity of active sites at atomic scale may be more conducive to their synergistic effect when the diffusional limitation from zeolitic channel is minimized. These results had presented new direction for the preparation of efficient bifunctional catalysts in hydroisomerization of linear alkanes.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Yu Zhou,Ning Li,Caiping Ma,Xiaohua Shen,Xiaofeng Li,Baojun Wang,Lixia Ling
Ga-ZSM-5 zeolite has excellent performance for methanol to aromatics (MTA) reactions, but introducing Ga metal into ZSM-5 zeolite leads to a complex acid species. The present study investigated the effect of Ga metal content on the acid amount and MTA reaction products in the hydrothermal synthesis of Ga-ZSM-5 zeolite. Lewis acid mainly formed at a Ga/Al ratio below 2.0, and at a Ga/Al ratio higher than 2.0, framework Ga species formed, increasing Brønsted acid content. Ga 2.0 -ZSM-5 zeolite exhibited the lowest B/L acid ratio (0.48), excellent BTX selectivity (40.26%), and the highest H 2 selectivity (8.93%). This finding indicates the most pronounced synergistic hydrogenation of Brønsted and Lewis acids. Ga 3.0 -ZSM-5 produced more xylene with more Brønsted acid compared to Ga 1.0 -ZSM-5, although they both had the same B/L acid ratio. The alterations in acidic species at different content of Ga metal appear to be conducive to the regulation of acidity in Ga-ZSM-5 zeolites.
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2014
·
IF 1.552
Xingcui Guo,Xicheng Wang,Jing Guan,Xiufang Chen,Zhangfeng Qin,Xindong Mu,Mo Xian
Ru particles were introduced into the zeolite ZSM-5 (MFI) by either a conventional impregnation method or a one-step template-free process. The resultant materials were characterized by X-ray diffraction, N 2 adsorption-desorption, scanning electron microscopy, transmission electron microscopy, NH 3 and CO 2 temperature-programmed desorption. The results indicated that the Ru species in ZSM-5 catalysts prepared via the latter approach (designated as Ru/ZSM-5-TF) were highly dispersed in the ZSM-5 framework structure and this material exhibited high catalytic performance during the hydrogenation of D-glucose to D-sorbitol. The conversion of D-glucose was as high as 99.6% with D-sorbitol selectivity reaching 99.2%, exceeding the performance of Ru/ZSM-5 catalysts prepared by the conventional impregnation method with microporous or desilicated ZSM-5 supports. More importantly, this catalyst showed high stability against leaching and poisoning and could be reused several times. The extensive dispersion of the Ru species, strong interaction between the Ru species and the ZSM-5, and the suitable surface acidity-basicity balance of the Ru/ZSM-5-TF were all critical factors leading to excellent catalytic behavior and stability.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2023
·
IF 4.3
Xi-shuo Wang,Ying-jiao Li,Ting-ting Qi,Ji-wen Fu,Guang-Wen Chu,Bao-chang Sun
In industry, H-type zeolites are usually synthesized under hydrothermal conditions in the sodium-containing system, in which great deal of ammonia nitrogen wastewater will be produced during the transformation of zeolites from Na-type to H-type. In this work, we prepared ZSM-5 zeolites in the sodium-free system using organic amines in a rotating packed bed (RPB), which can greatly reduce the amount of wastewater. It was found that the ZSM-5 zeolites synthesized by isopropanolamine (MIPA) had the highest acid amount with a value of 2.331 mmol/g compared to that by other three amines, and exhibits the highest conversion of benzaldehyde with a value of 77.63% in the acetal reaction of benzaldehyde and ethylene glycol . More importantly, RPB premixing can improve the transfer of Al into the framework of ZSM-5 zeolites relative to conventional stirring technique. This work provided a new route to prepare ZSM-5 zeolites with high acid amount in sodium-free system.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2016
·
IF 1.207
Fang Jin,Xianqiao Wang,Tieliang Liu,Linbo Xiao,Ming Yuan,Yangchun Fan
A new effective process to improve the utilization of industrial fluorosilicic acid of phosphate fertilizer by-product has been investigated to comprehensive application of the silicon and fluorine source. Two-step ammoniation was applied to recover high-quality silica. The recovered silica can be used to hydrothermal synthesize ZSM-5 zeolite without impurity phase contamination, which was confirmed by XRD, TG, SEM, BET and EDS characteristic techniques. It was found that with the increase of SiO 2 /Al 2 O 3 ratio and the extension of reaction time, the crystal type transform from the orthorhombic to the monoclinic phase. The impurity fluorine content of the recovered SiO 2 from H 2 SiF 6 has great influence on the hydrothermal process for ZSM-5 crystal structure formation. Moreover, the increase of fluorine ions content in the hydrothermal process can control the crystal morphology and size of synthesized ZSM-5. Catalytic properties of synthesized HZSM-5 with different SiO 2 /Al 2 O 3 ratio in transalkylation of toluene and 1,2,4-trimethylbenzene show good and stable catalytic performance. The ZSM-5 synthesized with recovered silica source exhibits similar catalyst life as the performance of small particle size HZSM-5, because the ZSM-5 synthesized with the silica source from industrial hexafluorosilicic acid prefers a thin disk crystal along the b axis direction, which shortens the diffusion distance of generated products.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nature Catalysis
·
2022
·Vol. 5
·期 1
·45-54
·
IF 40.706
Qi Guodong,Davies Thomas E.,Nasrallah Ali,Sainna Mala A.,Howe Alexander G. R.,Lewis Richard J.,Quesne Matthew,Catlow C. Richard A.,Willock David J.,He Qian,Bethell Donald,Howard Mark J.,Murrer Barry A.,Harrison Brian,Kiely Christopher J.,Zhao Xingling,Deng Feng,Xu Jun,Hutchings Graham J.
The oxidation of methane, the main component of natural gas, to selectively form oxygenated chemical feedstocks using molecular oxygen has been a long-standing grand challenge in catalysis. Here, using gold nanoparticles supported on the zeolite ZSM-5, we introduce a method to oxidize methane to methanol and acetic acid in water at temperatures between 120 and 240 °C using molecular oxygen in the absence of any added coreductant. Electron microscopy reveals that the catalyst does not contain gold atoms or clusters, but rather gold nanoparticles are the active component, while a mechanism involving surface adsorbed species is proposed in which methanol and acetic acid are formed via parallel pathways.
研究领域:
催化化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Qingfeng Che,Minjiao Yang,Xianhua Wang,Xu Chen,Wei Chen,Qing Yang,Haiping Yang,Hanping Chen
Dual catalysts are proposed in this study to convert biomass pyrolysis vapors into aromatics. Metal oxides (CaO, Al 2 O 3 , and ZnO) and ZSM-5 were introduced into the catalytic upgrading process. In the pyrolysis process without ZSM-5, the addition of CaO effectively removed carboxylic organics and methoxyphenols, reducing the product yield with a hydrogen to carbon ratio of 0, and the size of phenol compounds. The addition of Al 2 O 3 greatly promoted the cracking of oxygenates with molecular weight above 109 g mol −1 , such as large-size methoxyphenols and sugars. It is found that the upgraded pyrolysis volatiles are more conducive to conversion for aromatics with a ZSM-5 catalyst. The addition of CaO increased the selectivity of xylene (15.9%), while Al 2 O 3 promoted the selectivity of toluene (18.3%). The highest yield of aromatics was obtained with CaO-ZSM-5 dual catalyst system, which was boosted by 6.14% compared to that of pure ZSM-5. To explore more effective methods for aromatics production, the arrangement of catalysts and temperature condition were investigated. Mixing CaO with biomass produced more aromatics than other methods, and the most suitable temperature for the formation of aromatic hydrocarbons was 600 °C.
研究领域:
能源科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Mengke Liu,Yingnan Zhao,Huawang Zhao,Xianghui Li,Yuhan Ma,Xin Yong,Hong Chen,Yongdan Li
A number of M-Cu-ZSM-5 (M = La, Ni, La-Ni) samples were prepared via an aqueous solution ion-exchange method. The co-doping with Ni and La into a Cu-ZSM-5 catalyst enhanced the NO decomposition activity in a temperature range 350–550 °C. The characterization results indicate that doping with La effectively improved the dispersion of the Cu species forming more Cu 2+ ions in the sample, while the effect of Ni is likely to facilitate the implantation of Cu 2+ to form (Cu 2+ -O 2– -Cu 2+ ) 2+ dimers. The synergistic effect of La and Ni contributes to the increased (Cu 2+ -O 2− -Cu 2+ ) 2+ content in the co-doped sample, thus enhancing the NO decomposition activity.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Quan Zhang,Wei Huang,Wenhao Cui,Xingzong Dong,Guangye Liu,Yunpeng Xu,Zhongmin Liu
The acidity and porosity of zeolite catalysts are crucial parameters affecting the catalytic performance. In this work, alkali treatment and metal species loading were used to modify the porosity and acidity of ZSM-5 zeolite to prepare an efficient catalyst for the 1,2-dichloroethane cracking reaction. After optimization, the highly active catalyst Zn (1%) /ZSM-5-120 was obtained, and 78% conversion of EDC and 99% selectivity toward VCM could be achieved under the conditions of 300 °C and 3.0 h −1 (WHSV). A detailed investigation was conducted on the effects of acidity, texture properties and metal species loaded on ZSM-5 zeolite on the 1,2-dichloroethane cracking reaction.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2014
·
IF 2.637
Chuan-Jun Yue,Miao-Miao Gan,Li-Ping Gu,Ya-Feng Zhuang
Cu/ZSM-5 prepared by in situ impregnated reduction was used for the catalytic dehydration of glycerol under solvent-free conditions. The catalyst was characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), ammonia temperature programmed desorption (NH 3 -TPD), and thermogravimetry-differential scanning calorimetry (TG-DSC) analyses. Results showed that the nano-copper in Cu/ZSM-5 was evenly distributed onto the surface of ZSM-5 pores. Under the optimum conditions of the catalytic dehydration of glycerol, conversion was 92.1 wt.%. The selectivities of acrolein and acetol were 80.4 wt.% and 11.5 wt.%, respectively. Moreover, the low temperature favored for acetol selectivity. The synergic catalysis of Cu and ZSM-5 through the enol intermediate was responsible for the selectivity in the catalytic dehydration of glycerol.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2025
·Vol. 15
·期 11
·797
·
IF 4.3
Mingbo Guo,Yijun Wang,Lei Zhang,Junran Lu,Chang Gong,Wanning Zhang,Yuxi Fang,Xinyuan Zhu,Shunai Che
Size restrictions pose increasing challenges to the acoustic performance of microspeakers in portable devices as the size of such devices, and thus the back volume of microspeakers, continues to shrink. Filling the back volume with porous materials, such as zeolites, has been proved to be an effective strategy for improving acoustic performance. In this work, hierarchically structured ZSM-5 zeolites with abundant mesopores were synthesized via the traditional hydrothermal method by adjusting the SiO2/Al2O3ratios (SAR), and their pore structures and morphologies were systematically investigated. Their acoustic enhancement performance was evaluated using a commercial microspeaker. Based on their acoustic properties, the influence of pore structure on acoustic performance was further studied. The ZSM-5 zeolite sample with an SAR of 614, which exhibited the maximum mesopore volume, demonstrated exceptional acoustic enhancement performance with a resonance offset of 199.53 Hz and an enhanced sound pressure level of 4.74 dB at 500 Hz. The presence of mesopores significantly facilitates diffusion within the zeolite crystals, enabling air molecules to access more micropores for efficient sorption–desorption processes during diaphragm vibration in microspeakers. Furthermore, supermicropores were found to contribute to improved performance by adsorbing air molecules during diaphragm vibration, complementing the role of micropores.
研究领域:
材料科学
·
声学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）