【摘要】 首次采用干粉法在Na2O-SiO2-Al2O3-NaCl体系中合成出高硅/铝比丝光沸石。采用XRD和吡啶吸附红外光谱等物理分析手段对产物结构、酸性分布等物性进行了表征,考察了合成条件对丝光沸石晶化的影响,以及丝光沸石应用于二甲苯异构化反应的催化性能。结果表明,n(SiO2)/n(Al2O3)、n(OH-)/n(SiO2)及n(H2O)/n(SiO2)(摩尔比)对结晶的影响很大;较理想的初始凝胶配比n(SiO2)/n(Al2O3)为8～20、n(OH-)/n(SiO2)为0.22～0.46、n(H2O)/n(SiO2)为2～6。XRD谱图中(200)、(202)晶面衍射峰强度之比值(I9.6/I25.6)与丝光沸石的硅/铝比呈现很好的线性关系;n(SiO2)/n(Al2O3)=13.53的丝光沸石样品具有适当的酸量及酸性分布,在较高空速下,其C8芳烃异构化反应活性与对二甲苯选择性较高。更多还原

【Abstract】 Mordenite with high silica-alumina ratio was first prepared by dry powder method at Na2O-SiO2-Al2O3-NaCl system with satisfactory efficiency.The product was characterized by means of XRD and FT-IR for its structure and acidity distribution,et al.The influences of synthesis conditions on crystallization of mordenite were investigated,and the reaction activity and the selectivity for p-xylene of the prepared mordenite in catalytic isomerization of C8 aromatics were also studied.The results indicated that crystallization of mordenite was strongly affected by the gel composition,such as n(SiO2)/n(Al2O3),n(OH-)/n(SiO2) and n(H2O)/n(SiO2).The high crystallinity of mordenite could be obtained at n(SiO2)/n(Al2O3) of 8-20,n(OH-)/n(SiO2) of 0.22-0.46,n(H2O)/n(SiO2) of 2-6.The fine linear relation between I9.6/I25.6 on the surface of crystal(200),(202) and n(SiO2)/n(Al2O3) was observed.The catalysis reaction activity and selectivity for p-xylene of the mordenite with n(SiO2)/n(Al2O3) of 13.53 in terms of isomerization of C8 aromatics were better at high space velocity.更多还原