INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2023
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IF 4.2
Chuang Liu,Jun Liang,Duozheng Ma,Xiangcheng Li,Liyuan Li,Yu Wang,Tiezhu Zhang,Wenhua Fu,Zhendong Wang,Weimin Yang
The synthesis of zeolite nanosheets is an effective strategy to obtain advanced catalysts with enhanced catalytic performance due to the improved diffusion properties. ZSM-22 zeolite nanosheets (F-ZSM-22, U-ZSM-22) with a controllable orientation and a thickness of less than 20 nm were obtained through hydrothermal crystallization by introducing NaF or urea into the synthetic system of conventional ZSM-22 (C-ZSM-22). In the presence of both NaF and urea, a zeolite nanosheet (FU-ZSM-22) with a decreased width was synthesized. In comparison with C-ZSM-22, all ZSM-22 nanosheets displayed better diffusion properties. On testing catalysts in the methanol-to-hydrocarbon reaction, ZSM-22 nanosheets showed better stability than C-ZSM-22, and FU-ZSM-22 was the best catalyst.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 35
·16752-16763
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IF 3.925
Kai Guo,Aizeng Ma,Zijian Wang,Jinzhi Li,Bingfeng Wu,Tong Liu,Dadong Li
The design of various hierarchical structures and morphologies of ZSM-22 zeolite catalysts is attempted through a post-treatment using different concentrations of NaOH and subsequently treating with HCl solution including fluosilicic acid (H2SiF6) and then loading Pt on their surfaces. The effects of samples on textural characters, acidity, as well as n-heptane catalytic hydroisomerization evaluation were examined. The formation process of the hierarchical structures was further investigated. Test and evaluation results indicated that samples treated with 0–0.5 M NaOH and subsequently treated with 6.0 M HCl and 0.1 M H2SiF6 were much more controllable and reasonable due to the better structure-activity relationship of the catalyst by changing crystal morphologies and introducing hierarchical structures. Indeed, PZH-0.3 exhibited 81.1% of the highest n-heptane conversion and 76.4% of total i-heptane yield in the n-heptane catalytic hydroisomerization process at 260 °C, PZH-0.5 displayed 13.6% of the maximum multi-branched i-heptane yield, which was above 104.1% in comparison with PZ-0 at 320 °C. Moreover, PZH-0.3 presented the highest n-butane yield, which possessed a proportion of 65.9% in the butane component of cracking products at 340 °C and improved an average of 16% and 22 times when utilizing PZ-0 and Pt/ZSM-5 catalysts. Additionally, the mechanism of the reaction process is briefly depicted according to the distribution of the reaction products. The regulation of zeolite both on crystal morphologies and pore hierarchy has obvious advantages in the hydroisomerization process, which can improve the composition of multi-branched isomers with high octane number effectively as well as supply raw materials for the chemical industry.
研究领域:
催化化学
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石油化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2022
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IF 3.656
Le Wang,Pengyu Niu,Hongjuan Xi,Xiaoyan Chen,Congbiao Chen,Zhongyi Ma,Litao Jia,Bo Hou,Debao Li
ZSM-22 zeolite with core-shell structure was synthesized via a facile one-pot/three-step synthesis route. The crystallinity , morphology, chemical composition , textural and acidic properties of core-shell ZSM-22 were characterized to reveal the formation mechanism in the crystallization process by various techniques, such as XRD , SEM, ICP , FTIR, Py-IR, N 2 -physisorption, and XPS analysis . The as-fabricated core-shell zeolites possess increased specific surface area (>150 m 2 g −1 ) and decreased Brønsted acid sites (81 μmol g −1 ). The acid sites located on the external surface of Al-rich zeolite nanocrystals were passivated by the epitaxy growth of high silica ZSM-22 shell. The size (radial dimension tune in the 30–65 nm range, axial dimension tune in 100–350 nm), structural properties, and acidity property of core-shell ZSM-22 can be adjusted freely by only modulating the alkalinity of the synthetic system in separate steps without adding silicon source and OSDAs. Moreover, it provides excellent tunability and controllability to both the size of products and the thickness of the Si-rich shell. The synthesis method herein may provide a generic platform for the design of other core–shell zeolites with potentially broader applicability.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2019
·Vol. 43
·期 35
·13967-13978
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IF 3.069
Qiang Ning,Huaike Zhang,Yurong He,Zhiqiang Chen,Suyao Liu,Jie Ren
Small Pt particles (about 1.2 nm) were highly dispersed on ZSM-22 zeolites via a strong electrostatic adsorption (SEA) method and exhibited a promotion effect on the catalytic performance in n-dodecane isomerization in comparison with the conventional catalyst. Several promoters (Ce, La, and Re) were introduced to further improve the aggregation resistance of the small Pt particles. A series of characterization including H2-TPR, XPS and STEM as well as DFT calculations provided solid evidence that the strong interaction between Pt and promoter species not only effectively hinders the Pt aggregation but also alters the electronic state of the Pt sites. Moreover, Ce and La promoters also lead to a slightly improved amount of B acid sites determined by Py-FTIR. Thus, improved activity and selectivity were achieved on a Ce-modified catalyst due to the better balanced bifunctionality between the slightly increased acidity of zeolites and electron-deficiency of Pt. The electron-rich Pt sites are responsible for the significant increase of CH4 selectivity and the decrease of total isomer selectivity in n-dodecane isomerization. In addition, a high-temperature reduction test revealed the higher isomerization activity and selectivity (about 10% higher than the unmodified catalyst) of the Ce-modified catalyst owing to the strong bond of Pt–O–Ce, further confirming the positive effect of the Ce promoter on the sintering resistance of small Pt particles.
研究领域:
催化化学
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材料科学
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计算化学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
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2019
·Vol. 9
·期 11
·2812-2827
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IF 5.726
Suyao Liu,Yurong He,Huaike Zhang,Zhiqiang Chen,Enjing Lv,Jie Ren,Yifeng Yun,Xiaodong Wen,Yong-Wang Li
Ga-Doped ZSM-22 zeolites were synthesized successfully via a hydrothermal method by directly incorporating Ga species into the zeolite framework. It appeared that the as-prepared Ga-substituted zeolites possessed high crystallinity, uniform morphology and open pore structure. The XRD, FTIR, XPS as well as 71Ga and 29Si MAS NMR results confirmed the presence of Ga species in the framework of zeolites and the formation of the Ga–OH–Si group, thus leading to a significant decrease of Brønsted acidity because of the lower acidity of the Ga–OH–Si bridge hydroxyl compared to that of the Si–OH–Al group. These characteristics ensured that the Pt-loading [Al, Ga]-ZSM-22 catalyst exhibited lower cracking activity and higher selectivity (about 78.2% at 90.5% of conversion) in the n-dodecane isomerization than the parent Pt/ZSM-22 catalyst, due to the more balanced bifunctionality between acid sites and metal sites. DFT calculations revealed that Al and Ga incorporation was mostly prevalent at the T2, T3 and T4 sites, while Fe heteroatom substitution occurred equivalently in four sites. Bader charge analysis suggested that the acidity decreased in the order of Al-ZSM-22 > Ga-ZSM-22 > Fe-ZSM-22, and the cracking activity exhibited the order of Al-ZSM-22 ≫ Ga-ZSM-22 > Fe-ZSM-22. Therefore, it could be concluded that the isomerization was facilitated by the combination of the heteroatom location and the acidity strength. Remarkably, no significant decline of crystallinity and special surface area of Ga-doped zeolites was observed after the high temperature calcination, revealing higher stability of Ga than Fe in the zeolite framework.
研究领域:
催化化学
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材料科学
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理论化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2021
·
IF 3.764
Le Wang,Pengyu Niu,Hongjuan Xi,Xiaoyan Chen,Congbiao Chen,Zhongyi Ma,Litao Jia,Bo Hou,Debao Li
A facile method was developed to precisely control the particle size of nanosized ZSM-22 zeolite with a range of 80–850 nm via a two-step crystallization procedure. Based on the ZSM-22 crystallization process, inhibiting or promoting the crystal growth and the fusion of nanocrystals are crucial to obtain specific sized ZSM-22. For this purpose, the crystallization process of ZSM-22 was quenched after 12 h to obtain abundantly viable ZSM-22 nanocrystals formed on the aluminosilicate amorphous particles. In the recrystallization process, the viable nanocrystals continued to crystallize and the dissolved amorphous particles released Si and Al species as nutrients. After further simplifying the procedures, some additives were used at the very beginning of the recrystallization procedure. Not only small crystals can be formed but also the crystal length of ZSM-22 along the [001] direction varies from 80 to 850 nm. We have systematically investigated the influencing factors such as alkali metal cations and the alkalinity of the synthesis system on the mechanism of ZSM-22 zeolite nucleation and growth and the morphology and yield of products. We report a facile synthetic route for size-controlled nanosized ZSM-22 by decoupling its nucleation and growth processes for the first time.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Jinhui Song,Tianfu Zhang,Mengjiao Xing,Junfeng Zhou,Lu Tang,Jiaxin Xie,Zimin Peng,Wenyao Gu,Jianyu Tang,Suyao Liu,Tong Chang,Yi Liu,Yiwen Fang
With the potential application of biomass-derived feedstock upgradation to sustainable aviation fuels, it is essential to enhance the hydroisomerization performance of ZSM-22 zeolite while improving its resistance to residual oxygen-containing compounds. As the defect sites in the ZSM-22 zeolite, the abundant Si-OH groups are closely related to the catalytic performance and stability, serving as the main attack sites for the generated water. In this work, liquid-mediated defect-healing treatment is performed to heal Si-OH to Si-O-Si, leading to the enhancement of the crystallinity and pore connectivity without affecting the Si/Al, micropore volume, and morphology and preventing the micropores blockage and dealumination caused by conventional silylation and silication procedures. The outcome of the declined Si-OH groups is the reduction of the Lewis acid site without altering the Brønsted acidity. In the n-dodecane hydroisomerization, the catalyst obtained by the liquid-mediated defect-healing treatment route shows an increased conversion and isomer yield compared to the parent and healed catalysts prepared by other healing methods. This is mainly due to enhanced confinement of the micropore void, resulting in decreased apparent activation energy and reduced yield to multi-branched isomers prone to cracking. Furthermore, the healed catalyst exhibits improved resistance and structure stability in the hydroisomerization of feedstocks containing butanol. The work provides a prospective application of ZSM-22 zeolite in the hydroisomerization for complex and severe reactants through the essential Si-OH healing method.
研究领域:
催化化学
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材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 24
·6407-6419
·
IF 5.365
Pengyu Niu,Hongjuan Xi,Jun Ren,Minggui Lin,Qiang Wang,Xiaoyan Chen,Pengfei Wang,Litao Jia,Bo Hou,Debao Li
A core–shell ZSM-22 (Z@S) was synthesized via epitaxial growth. The characterization results of Z@S validated that the acid sites located on the external surface of core ZSM-22 were passivated by the epitaxial shell of highly siliceous ZSM-22 and the acid strength of ZSM-22 remained unchanged. For comparison, highly siliceous and boron-containing ZSM-22 were also synthesized and characterized. In n-dodecane hydroisomerization, highly siliceous ZSM-22 almost without acid sites at the external surface achieved a much higher iso-dodecane selectivity than boron-containing ZSM-22 with weak acid sites. Z@S with strong acid sites and passivated surface acidity showed high activity and favored pore mouth catalysis but exhibited a lowered iso-dodecane selectivity. The reduced external surface acid sites enhanced the diffusion of n-alkane into the micropores, leading to severe cracking reaction caused by acid sites on the internal surface. Further modifying Z@S via micropore blockage could greatly inhibit cracking reaction inside the micropores and confine isomerization at the pore mouth of ZSM-22. This new ZSM-22 catalyst achieved higher activity and a higher iso-dodecane yield than catalysts with weak acidity.
研究领域:
催化化学
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材料科学
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石油化工
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纳米结构材料
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表面化学
✓ 已验证
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2025
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IF 3.4
Jinhui Song,Jiaxin Xie,Tianfu Zhang,Mengjiao Xing,Zimin Peng,Wenyao Gu,Jianyu Tang,Lu Tang,Suyao Liu,Yi Liu,Tong Chang,Yiwen Fang
Advancing the conventional hydrothermal and ionic liquid-assisted synthesis methodologies to produce ZSM-22 zeolites with similar characteristics yet notably distinct defect sites holds substantial significance in elucidating their influence on shape selectivity and hydroisomerization performance. This study investigated the impact of the initial gel ratio and synthesis parameters on the ionic liquid-assisted crystallization process and the crystal size of the ZSM-22 zeolite. The NH4F feed exhibits a minimal effect on the crystallization process, in contrast to the beneficial effect of improved ionic liquid and decreased water feed on substantially diminishing the crystal size of the resulting zeolites, which exhibit a morphology similar to that of the ZSM-22 zeolite obtained through the conventional synthesis route. Furthermore, the investigation into the crystallization process revealed that both ionic liquids and high temperatures play indispensable roles in accelerating the nucleation and crystal growth of ZSM-22 zeolite. When applied in the n-dodecane hydroisomerization, the nanosized ZSM-22 zeolites prepared by ionic liquid-assisted route exhibit remarkable isomer yield (above 72%), surpassing the conventional and large-size ZSM-22 zeolites. After the product distribution analysis, it is evident that the fewer Si–OH defect sites and the correspondingly strict confinement environment effectively limit the formation of the multibranched intermediates prone to crack, which ultimately improves the hydroisomerization performance, intrinsically reflecting the shape selectivity of the 10-membered ring zeolite by eliminating the interference of the framework defect sites. This work emphasizes the exceptional hydroisomerization performance of the ZSM-22 zeolite, highlighting the significance of its efficient synthesis and wide application.
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
·
2018
·
IF 4.521
Pengyu Niu,Ping Liu,Hongjuan Xi,Jun Ren,Minggui Lin,Qiang Wang,Xiaoyan Chen,Litao Jia,Bo Hou,Debao Li
The formation of centrally branched iso-dodecane was controlled by absorption modes of alkene intermediates on ZSM-22, which included pore mouth type and key lock type. In this paper, we have designed and synthesized two kinds of ZSM-22 catalysts for selective formation of iso-dodecane with branched chain at more central positions from n -dodecane hydroisomerization. Aluminosilicate ZSM-22 was modified via carbonization of template to block the micropores and borosilicate ZSM-22 was synthesized. The characterization results and performance evaluation validated that micropore blockage could limit the pore mouth type at low reaction temperatures which favored the formation of iso-dodecane with side chain near the end of the carbon chain. Owing to the weak acid strength, higher temperatures, which favored the key lock mode, were needed to run the n -dodecane hydroisomerization over Pt/borosilicate ZSM-22. Both the two strategies for catalyst design achieved key lock adsorption mode and improvement of the selectivity for centrally branched iso-dodecane. Most importantly, weak acid sites on borosilicate ZSM-22 could catalyze double-bond isomerization reactions, which enhanced centrally branched iso-dodecane distribution up to more than 47%. Our research provides a prospective strategy for selective formation of centrally branched iso-alkanes and Pt/borosilicate ZSM-22 is expected to have potential applications in n-alkane hydroisomerization.
研究领域:
催化化学
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石油炼制
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材料化学
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工业化学
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能源化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）