{"title":"一维沸石支撑铂催化剂上烷烃加氢异构化的形状选择:Pt/ZSM-48 与 Pt/ZSM-22 的比较","authors":"Sida Ge, Zunlong Hu, Haodong Xie, Shiao Gao, Zhuwen Zhang, Zhijie Wu","doi":"10.1016/j.micromeso.2024.113179","DOIUrl":null,"url":null,"abstract":"<div><p>Hydroisomerization of long-chain <em>n</em>-alkanes plays a vital role in petrochemical and coal chemical industries, because it can produce high-quality hydrocarbon fuels and lubricant base oils. ZSM-48 (0.56 × 0.53 nm) and ZSM-22 (0.57 nm × 0.46 nm) are characteristic of one-dimensional 10-member ring zeolites suitable for <em>n</em>-alkanes hydroisomerization reaction. Here, the effect of the structure difference between ZSM-48 and ZSM-22 zeolites on hydroisomerization is titrated by the isobutane and <em>n</em>-dodecane. The product distribution of hydroisomerization of isobutane to <em>n</em>-butane shows the reaction pathway on Pt/ZSM-48 and Pt/ZSM-22, in which the monomolecular hydroisomerization of isobutane is involved within the active sites in zeolite channels, while the polymerization-cracking bimolecular reaction occurs on the pore-mouth of zeolite. Pt/ZSM-48 zeolite, possessing larger channel and aperture size than those of Pt/ZSM-22, is more conducive to the diffusion of butane molecules and bimolecular polymerization. Therefore, the isobutane conversion (14 %) on Pt/ZSM-48 produces less C<sub>1</sub>+C<sub>2</sub> (1.7 wt% vs. 3.4 wt%) and more C<sub>3</sub>+C<sub>5</sub>+C<sub>8</sub> (19.2 wt% vs. 16.9 wt%). For the hydroisomerization of <em>n</em>-dodecane, the <em>iso</em>-dodecane selectivity of Pt/ZSM-48 (43.3 wt%) is significantly higher than that of Pt/ZSM-22 (12.4 wt%) at the similar <em>n</em>-C<sub>12</sub> conversion (40 %). Compare with the isomers of Pt/ZSM-22, the mono-branched isomers with methyl near the middle of the chains and multi-branched isomers are more easily formed on Pt/ZSM-48, which is conducive to the “key-lock” catalysis mechanism. The larger pore size of ZSM-48 is conducive to <em>n</em>-C<sub>12</sub> insertion into zeolite pores, methyl migration and isomer diffusion, and its adjacent pores are more compatible with double-branched isomers. In addition, a high selectivity of C<sub>4</sub>∼C<sub>5</sub> alkanes (53.2 wt%) on Pt/ZSM-22 and a high selectivity of C<sub>6</sub>∼C<sub>9</sub> alkanes (44.7 wt%) on Pt/ZSM-48 show obvious difference in cracking product distribution, implying different position of methyl groups in <em>i</em>-C<sub>12</sub> isomers on Pt/ZSM-22 and Pt/ZSM-48 samples, respectively. The present comparison between Pt/ZSM-48 and Pt/ZSM-22 benefits the selection and development of one-dimensional zeolitesupported metal catalyst in a wide range of hydro-processing reactions.</p></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Shape selection of alkane hydroisomerization over one-dimensional zeolite supported Pt catalyst: Pt/ZSM-48 versus Pt/ZSM-22\",\"authors\":\"Sida Ge, Zunlong Hu, Haodong Xie, Shiao Gao, Zhuwen Zhang, Zhijie Wu\",\"doi\":\"10.1016/j.micromeso.2024.113179\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Hydroisomerization of long-chain <em>n</em>-alkanes plays a vital role in petrochemical and coal chemical industries, because it can produce high-quality hydrocarbon fuels and lubricant base oils. ZSM-48 (0.56 × 0.53 nm) and ZSM-22 (0.57 nm × 0.46 nm) are characteristic of one-dimensional 10-member ring zeolites suitable for <em>n</em>-alkanes hydroisomerization reaction. Here, the effect of the structure difference between ZSM-48 and ZSM-22 zeolites on hydroisomerization is titrated by the isobutane and <em>n</em>-dodecane. The product distribution of hydroisomerization of isobutane to <em>n</em>-butane shows the reaction pathway on Pt/ZSM-48 and Pt/ZSM-22, in which the monomolecular hydroisomerization of isobutane is involved within the active sites in zeolite channels, while the polymerization-cracking bimolecular reaction occurs on the pore-mouth of zeolite. Pt/ZSM-48 zeolite, possessing larger channel and aperture size than those of Pt/ZSM-22, is more conducive to the diffusion of butane molecules and bimolecular polymerization. Therefore, the isobutane conversion (14 %) on Pt/ZSM-48 produces less C<sub>1</sub>+C<sub>2</sub> (1.7 wt% vs. 3.4 wt%) and more C<sub>3</sub>+C<sub>5</sub>+C<sub>8</sub> (19.2 wt% vs. 16.9 wt%). For the hydroisomerization of <em>n</em>-dodecane, the <em>iso</em>-dodecane selectivity of Pt/ZSM-48 (43.3 wt%) is significantly higher than that of Pt/ZSM-22 (12.4 wt%) at the similar <em>n</em>-C<sub>12</sub> conversion (40 %). Compare with the isomers of Pt/ZSM-22, the mono-branched isomers with methyl near the middle of the chains and multi-branched isomers are more easily formed on Pt/ZSM-48, which is conducive to the “key-lock” catalysis mechanism. The larger pore size of ZSM-48 is conducive to <em>n</em>-C<sub>12</sub> insertion into zeolite pores, methyl migration and isomer diffusion, and its adjacent pores are more compatible with double-branched isomers. In addition, a high selectivity of C<sub>4</sub>∼C<sub>5</sub> alkanes (53.2 wt%) on Pt/ZSM-22 and a high selectivity of C<sub>6</sub>∼C<sub>9</sub> alkanes (44.7 wt%) on Pt/ZSM-48 show obvious difference in cracking product distribution, implying different position of methyl groups in <em>i</em>-C<sub>12</sub> isomers on Pt/ZSM-22 and Pt/ZSM-48 samples, respectively. The present comparison between Pt/ZSM-48 and Pt/ZSM-22 benefits the selection and development of one-dimensional zeolitesupported metal catalyst in a wide range of hydro-processing reactions.</p></div>\",\"PeriodicalId\":392,\"journal\":{\"name\":\"Microporous and Mesoporous Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2024-05-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Microporous and Mesoporous Materials\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1387181124002014\",\"RegionNum\":3,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microporous and Mesoporous Materials","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1387181124002014","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
Shape selection of alkane hydroisomerization over one-dimensional zeolite supported Pt catalyst: Pt/ZSM-48 versus Pt/ZSM-22
Hydroisomerization of long-chain n-alkanes plays a vital role in petrochemical and coal chemical industries, because it can produce high-quality hydrocarbon fuels and lubricant base oils. ZSM-48 (0.56 × 0.53 nm) and ZSM-22 (0.57 nm × 0.46 nm) are characteristic of one-dimensional 10-member ring zeolites suitable for n-alkanes hydroisomerization reaction. Here, the effect of the structure difference between ZSM-48 and ZSM-22 zeolites on hydroisomerization is titrated by the isobutane and n-dodecane. The product distribution of hydroisomerization of isobutane to n-butane shows the reaction pathway on Pt/ZSM-48 and Pt/ZSM-22, in which the monomolecular hydroisomerization of isobutane is involved within the active sites in zeolite channels, while the polymerization-cracking bimolecular reaction occurs on the pore-mouth of zeolite. Pt/ZSM-48 zeolite, possessing larger channel and aperture size than those of Pt/ZSM-22, is more conducive to the diffusion of butane molecules and bimolecular polymerization. Therefore, the isobutane conversion (14 %) on Pt/ZSM-48 produces less C1+C2 (1.7 wt% vs. 3.4 wt%) and more C3+C5+C8 (19.2 wt% vs. 16.9 wt%). For the hydroisomerization of n-dodecane, the iso-dodecane selectivity of Pt/ZSM-48 (43.3 wt%) is significantly higher than that of Pt/ZSM-22 (12.4 wt%) at the similar n-C12 conversion (40 %). Compare with the isomers of Pt/ZSM-22, the mono-branched isomers with methyl near the middle of the chains and multi-branched isomers are more easily formed on Pt/ZSM-48, which is conducive to the “key-lock” catalysis mechanism. The larger pore size of ZSM-48 is conducive to n-C12 insertion into zeolite pores, methyl migration and isomer diffusion, and its adjacent pores are more compatible with double-branched isomers. In addition, a high selectivity of C4∼C5 alkanes (53.2 wt%) on Pt/ZSM-22 and a high selectivity of C6∼C9 alkanes (44.7 wt%) on Pt/ZSM-48 show obvious difference in cracking product distribution, implying different position of methyl groups in i-C12 isomers on Pt/ZSM-22 and Pt/ZSM-48 samples, respectively. The present comparison between Pt/ZSM-48 and Pt/ZSM-22 benefits the selection and development of one-dimensional zeolitesupported metal catalyst in a wide range of hydro-processing reactions.
期刊介绍:
Microporous and Mesoporous Materials covers novel and significant aspects of porous solids classified as either microporous (pore size up to 2 nm) or mesoporous (pore size 2 to 50 nm). The porosity should have a specific impact on the material properties or application. Typical examples are zeolites and zeolite-like materials, pillared materials, clathrasils and clathrates, carbon molecular sieves, ordered mesoporous materials, organic/inorganic porous hybrid materials, or porous metal oxides. Both natural and synthetic porous materials are within the scope of the journal.
Topics which are particularly of interest include:
All aspects of natural microporous and mesoporous solids
The synthesis of crystalline or amorphous porous materials
The physico-chemical characterization of microporous and mesoporous solids, especially spectroscopic and microscopic
The modification of microporous and mesoporous solids, for example by ion exchange or solid-state reactions
All topics related to diffusion of mobile species in the pores of microporous and mesoporous materials
Adsorption (and other separation techniques) using microporous or mesoporous adsorbents
Catalysis by microporous and mesoporous materials
Host/guest interactions
Theoretical chemistry and modelling of host/guest interactions
All topics related to the application of microporous and mesoporous materials in industrial catalysis, separation technology, environmental protection, electrochemistry, membranes, sensors, optical devices, etc.