| Properties and Characterization of Modified HZSM—5 Zeolites |
| |
| 引用本文： | Renqing Lü,Hejin Tangbo,Qiuying Wang,Shouhe Xiang.Properties and Characterization of Modified HZSM—5 Zeolites[J].天然气化学杂志,2003,12(1):56-62. |
| |
| 作者姓名： | Renqing Lü Hejin Tangbo Qiuying Wang Shouhe Xiang |
| |
| 作者单位： | [1]InstituteofNewCatalyticMaterials,DepartmentofMaterialChemistry,NankaiUniversity,Tianjin300071,China [2]CatalyticFactory,NankaiUniversity,Tianjin300071,China |
| |
| 基金项目： | Financial support from Catalytic Key Laboratory of China Petroleum and Natural Gas Group Corpo- ration (University of Petroleum) was greatly appre- ciated. We thank the National Science Foundation Committee for Grant NSFC 20233030. |
| |
| 摘 要： | Physicochemical and catalytic properties of phosphorus and boron modified HZSM-5 zeolites treated with 100% steam at 673K were investigated.The acidity and distribution of acidic sites were studied by infrared spectroscopy using pyridine as probe molecule and temperature programmed desortion (TPD) of ammonia.The structure of the samples was characterized by XRD,and the textural properties of the catalysts were determined by nitrogen isothermal adsorption-desorption measurements and scanning electron microscopy(SEM).The XRD results show that the modified samples have no novel crystalline phase,indicating a high dispersion of phosphorus and boron species.After treatment,the microporous volume and surface area of the samples markedly decrease,implying the bolockage of the channel.The nitrogen adsorption-desorption measurements suggest that the isothermal type of all samples is a combination of isothermal type Ⅰ and Ⅳ，and all hysteresis loops resemble the H4-type in the IUPAC classification.The total acidity of the modified samples,determined by pyrldine adsorption IR and TPD of ammonia,decreases in contrast to that of the parent HZSM-5.The conversion of n-heptane over P and B steammodified HZSM-5 is higher than that of P and B-modified HZSM-5 zeolites but lower than that of the parent HZSM-5.
|
| 关 键 词： | HZSM－5 沸石 分子筛 结构 性质 磷 硼 氮 等温吸附 |
Properties and Characterization of Modified HZSM-5 Zeolites |
| |
| Hejin Tangbo,Qiuying Wang,Shouhe Xiang.Properties and Characterization of Modified HZSM-5 Zeolites[J].Journal of Natural Gas Chemistry,2003,12(1):56-62. |
| |
| Authors: | Hejin Tangbo Qiuying Wang Shouhe Xiang |
| |
| Institution: | 1. Institute of New Catalytic Materials, Department of Material Chemistry, Nankai University, Tianjin, 300071, China 2. Catalytic Factory, Nankai University, Tianjin, 300071, China |
| |
| Abstract: | Physicochemical and catalytic properties of phosphorus and boron modified HZSM-5 zeolites treated with 100% steam at 673 K were investigated. The acidity and distribution of acidic sites were studied by infrared spectroscopy using pyridine as probe molecule and temperature programmed desorption (TPD) of ammonia. The structure of the samples was characterized by XRD, and the textural properties of the catalysts were determined by nitrogen isothermal adsorption-desorption measurements and scanning electron microscopy (SEM). The XRD results show that the modified samples have no novel crystalline phase, indicating a high dispersion of phosphorus and boron species. After treatment, the microporous volume and surface area of the samples markedly decrease, implying the blockage of the channel. The nitrogen adsorption-desorption measurements suggest that the isothermal type of all samples is a combination of isothermal type I and IV, and all hysteresis loops resemble the H4-type in the IUPAC classification. The total acidity of the modified samples, determined by pyridine adsorption IR and TPD of ammonia, decreases in contrast to that of the parent HZSM-5. The conversion of n-heptane over P and B steam-modified HZSM-5 is higher than that of P and B-modified HZSM-5 zeolites but lower than that of the parent HZSM-5. |
| |
| Keywords: | HZSM-5 zeolite steam treatment phosphorus boron secondary pore texture cracking activity |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《天然气化学杂志》浏览原始摘要信息 |
| 点击此处可从《天然气化学杂志》下载免费的PDF全文 |
