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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Xiaoxue Li,Xiaopo Niu,Shuaikang Zhu,Shuang Xu,Zheyuan Wang,Xiangwen Zhang,Qingfa Wang
Fabricating zeolite-supported catalysts with excellent catalytic performance for hydroconversion of bio-oils into high-quality fuels is still a great challenge. Herein, hierarchical ZSM-5 zeolites were successfully synthesized with 3-[(trimethoxysilyl) propyl] octadecyldimethylammonium chloride as a mesoporous template. The hierarchical ZSM-5 supported Pt catalysts (Pt/HZ-x) were used to enhance the hydrodeoxygenation of dibenzofuran into bicyclohexane, and the influence of acidity distribution on the reaction pathways was investigated by tailoring the Si/Al molar ratios (50, 75, and 100). For all catalysts, cycloalkanes were produced via the partial hydrogenation of the aromatic rings to generate tetrahydrodibenzofuran, followed by the cleavage of C—O bond. The optimal bicyclohexane selectivity (86.8%) was obtained on Pt/HZ-75 catalyst due to the good synergistic effect between metal dispersion and acid distribution. This catalyst also showed excellent stability because of its strong metal–support interactions. Even after reused five times, the catalytic activity was almost unchanged compared with the fresh one. Furthermore, the possible reaction pathways for conversion of dibenzofuran into bicyclohexane over Pt/HZ-x catalysts were developed.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Hongbing Wang,Yifei Yang,Shixiang Yu,Beibei Zhang,Junzhong Xie,Jun Chen,Dongping Wang,Bomin Feng,Changyin Zhong,Linsen Zhou,Wei Cui,Ding Ma,Yunxi Yao
Liquid-phase hydrogen isotopes exchange between hydrogen and water is a promising route for the hydrogen isotopes separation from water, catalyzed by the metal Pt with hydrophobic coating to surmount the flooding of reactive sites. However, poor water activation ability on Pt has limited the catalytic efficiency of Pt-based catalysts and hindered their application. Herein, we report a bifunctional Pt/ZSM-5 catalyst with hydrophobic modification by surface silylation for H 2 -HDO isotope catalytic exchange. The integration of metallic Pt and Brønsted acid (BA) sites in the microporous ZSM-5 boosts the catalytic efficiency of deuterium extraction by two orders of magnitude compared to commercial Pt-C at the optimum condition. In-situ spectroscopic and theoretical studies demonstrated that HDO-H 2 O preferentially adsorbs on BA sites (-Si-OH-Al) to form protonated water clusters stabilized by hydrogen-bonded network or to undergo the proton exchange to leave deuterium on zeolite framework as a new acidic site ([AlO 4 D]). Under the attractive interaction, the dissociated hydrogen on Pt clusters releases partial electrons to form positively-charged hydrogen, which further transfers to the [AlO 4 D] sites or protonated water clusters by interfacial spillover to produce the overcharging intermediates. These intermediates cleave their O-D bonds to form positively charged D, which ultimately spills back to Pt cluster and combines with the remaining electron to desorb in the form of HD. The synergistic effect between Pt and BA sites creates a new pathway of hydrogen transfer, which enables the more efficient hydrogen-water isotope exchange on the bifunctional Pt/ZSM-5 catalyst.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Shushu Huang,Dengyao Yang,Qianxi Tang,Wei Deng,Long Zhang,Ziye Jia,Zhengfang Tian,Qiang Gao,Limin Guo
In this study, the Pt-loaded ellipsoidal nanozeolite (Pt/ZSM-5-OS) was successfully synthesized by the mercaptosilane modification assisted Pt dispersion method and investigated for the catalytic combustion of toluene, which was used as a model compound of volatile organic compounds (VOCs). The catalytic activity evaluation showed that Pt/ZSM-5-OS exhibited an excellent activity in toluene catalytic combustion, with 90% conversion (T 90 ) occurring at just 164 °C. The catalytic activity was much higher than the catalyst prepared by traditional impregnation method (Pt/ZSM-5-IM, T 90 = 196 °C). In addition, the excellent properties of anti-water vapor and catalytic stability were observed for Pt/ZEM-5-OS. The as-prepared catalysts were characterized by X-ray diffraction (XRD), N 2 physisorption , scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Characterization of the as-prepared catalysts demonstrated that the enhanced catalytic performance was related to the improved Pt dispersion and higher Pt 0 proportion of Pt-ZSM-5-OS. Hence, Pt/ZSM-5-OS and its preparation method are attractive for the practical VOCs catalytic combustion.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2022
·Vol. 68
·期 7
·e17677
·
IF 4.167
Shen Hu,Jiaxuan Chen,Qunfeng Zhang,Junru Liu,Jinlin Meng,Guanghua Ye,Xinggui Zhou,Weikang Yuan
Surface barriers persist in the molecular transport across external crystal surface of zeolites, which brings strong influences on zeolite catalysis. This study probes the role of crystal-size–dependent surface barriers in zeolite catalysis, with n -pentane isomerization catalyzed by Pt/ZSM-5 as a model reaction system. Chemical liquid deposition of SiO 2 is performed to reduce surface barriers on ZSM-5 crystals with different sizes. After SiO 2 deposition, surface barriers on both small (266 nm) and large (1304 nm) crystals are significantly reduced, while the improvement in catalytic activity for the large crystals (76.1%–129.1%) is much higher than that for the small ones (−17.4% to 16.7%). For the large ZSM-5 crystals, diffusion limitation is stronger, and thus the effect of surface barriers on catalytic activity is more important. This study reveals the unique role of crystal-size–dependent surface barriers in zeolite catalysis, and understanding this is important for the optimal design of zeolite catalysts.
研究领域:
化学工程
·
材料科学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 46
·期 4
·1770-1778
·
IF 3.591
Xia Jiang,Feng Long,Qiaolong Zhai,Jiaping Zhao,Peng Liu,Junming Xu
Soap stocks are by-products obtained during the refining process of vegetable oil, and are mainly feedstocks to produce acidified oil. In this work, an efficient process was developed to convert soap stock into a high-quality biofuel with low impurity content. A combination of acidification and catalytic cracking reactions employed as pretreatment was investigated to decrease the impurity content in the soap stock feedstock for obtaining a value-added biofuel. A high olefin content (approximately 47%) pyrolytic oil was obtained during the pretreatment. For further improvement of the cold flow properties, hydro-isomerization of pyrolytic oil for the formation of iso-alkanes over the Ce–Pt/SAPO-11and Ce–Pt/ZSM-5 catalysts was then carried out. The isomerization reaction temperature could be decreased to 320 °C because of the approximately 47% olefin content. The cold filter plugging point (CFPP) of the resulting product could be obtained at −11 °C, and the sulfur content could be decreased to lower than 10 ppm, which could meet the EN and ASTM specifications.
研究领域:
化学工程
·
生物能源
·
催化
·
可再生能源
✓ 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）