CAJ | 학술논문

采用水热晶化的方法,通过改变凝胶Si/Fe比例合成了一系列不同铁含量的Fe/ZSM-5分子筛(凝胶投料硅铝比为100).在常压连续流动固定床反应器上,考察了Fe/ZSM-5分子筛用于催化甲苯甲醇烷基化的反应行为.采用X射线衍射、电子顺磁共振、N2物理吸附、氨程序升温脱附及吡啶吸附红外光谱等方法研究了Fe/ZSM-5分子筛的结构及孔结构性质和酸性.实验结果表明,在合成过程中引入铁原子,使部分铁原子进入分子筛骨架,并没有破坏ZSM-5分子筛的骨架结构,但降低了分子筛结晶度,改变了分子筛酸性质,降低了分子筛酸强度;Fe/ZSM-5抑制了积炭的形成,分子筛稳定性以及甲醇烷基化利用率得到明显提高.
채용수열정화적방법,통과개변응효Si/Fe비례합성료일계렬불동철함량적Fe/ZSM-5분자사(응효투료규려비위100).재상압련속류동고정상반응기상,고찰료Fe/ZSM-5분자사용우최화갑분갑순완기화적반응행위.채용X사선연사、전자순자공진、N2물리흡부、안정서승온탈부급필정흡부홍외광보등방법연구료Fe/ZSM-5분자사적결구급공결구성질화산성.실험결과표명,재합성과정중인입철원자,사부분철원자진입분자사골가,병몰유파배ZSM-5분자사적골가결구,단강저료분자사결정도,개변료분자사산성질,강저료분자사산강도;Fe/ZSM-5억제료적탄적형성,분자사은정성이급갑순완기화이용솔득도명현제고.
A series of Fe/ZSM-5 zeolites with different contents of Fe were hydrothermally synthesized by changing the Si/Fe ratio (the same gel of SiO2/Al2O3=100) and their catalytic performance for toluene alkylation with methanol was investigated in a continuous fluid fixed bed reactor at normal atmosphere. The structure, pore properties and acidity of Fe/ZSM-5 zeolites were characterized by X-ray diffraction,electronic paramagnet resonance, low temperature N2 adsorption, NH3-TPD and Py-IR. The results indicate that the partial introduction of Fe atoms into the zeolite frameworks in the synthetic process does not destroy the ZSM-5 framework structure, while it leads to the decrease in crystallization capacity, the change in acidity and the lowering in the acid strength. As a result, the coke formation during the alkylation reaction process is suppressed. Hence, the stability of zeolite and the utilization ratio of methanol are improved.