| 低硅铝比ZSM-5分子筛的合成及其正庚烷裂化反应性能 | |
| Synthesis of ZSM-5 zeolites with low silica-to-alumina ratio and its performance in the cracking of n-heptane | |
| 摘要: 以氨水为矿化剂，通过添加NH4+离子水热合成了具有较低骨架硅铝比的ZSM-5分子筛。通过X射线衍射（XRD）、扫描电镜（SEM）、固体核磁共振（MAS-NMR）等表征手段，研究了硅源、铝源、矿化剂、阳离子等对ZSM-5分子筛的结晶度、形貌尺寸和骨架硅铝比等的影响，研究了ZSM-5分子筛的骨架硅铝比对正庚烷催化裂化反应的影响。研究表明，投料硅铝比越低，铝原子越难进入到分子筛骨架中；当氨水为矿化剂、正硅酸四乙酯为硅源时可以合成骨架硅铝比较低的氢型ZSM-5分子筛，添加NH4+离子可以增强骨架铝的嵌入，进一步降低分子筛的骨架硅铝比（24.2）。正庚烷裂化反应结果表明，降低分子筛的骨架硅铝比可以提高正庚烷裂化反应的活性，但会降低低碳烯烃的选择性。 | |
| 关键词: ZSM-5分子筛 水热合成 低硅铝比 催化裂化 低碳烯烃 | |
| 基金项目: 国家自然科学基金（No.21908240）、中国石油科技创新基金项目（No.2020D-5007-0403）资助。 | |
| Abstract: ZSM-5 zeolites with low silica-to-alumina ratios were hydrothermally synthesized by adding NH4+ cation and using ammonia as mineralizer. The effects of Si source, Al source, mineralizer, and cation on the physiochemical properties of the prepared ZSM-5 zeolites were investigated. The crystallinity, crystal size, and silica-to-alumina ratio of zeolites were examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), solid state nuclear magnetic resonance (MAS-NMR), etc. The effect of silica-to-alumina ratio on the catalytic cracking of n-heptane was also studied. The results demonstrate that the lower the silica-to-alumina ratio feeding, the harder it is for Al atoms to insert into zeolite framework. Hydrogen-form ZSM-5 zeolites with low framework silica-to-alumina ratios could be synthesized with ammonia as mineralizer and tetraethyl orthosilicate as Si source. The addition of NH4+ cation enhanced the insertion of Al atom and the framework silica-to-alumina ratio of ZSM-5 further decreased to 24.2. The results of n-heptane cracking showed that the conversion of n-heptane was improved with decreasing the framework silica-to-alumina ratio of ZSM-5 zeolites, however, the selectivity of light olefins was decreased. | |
| Keywords: ZSM-5 zeolite hydrothermal synthesis low silica-to-alumina ratio catalytic cracking light olefin | |
| 投稿时间：2023-06-28 修订日期：2023-09-27 | |
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| 冯锐,申家铭,刘豹,李天泊,胡晓燕,闫新龙,张忠东.低硅铝比ZSM-5分子筛的合成及其正庚烷裂化反应性能[J].无机化学学报,2023,39(11):2042-2054. | |
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