通过水热晶化中的一步合成法合成了ZSM-5/MOR 复合分子筛,系统考察了硅铝比等对复合分子筛相对结晶度的影响。结果表明,当投料硅铝比为25 时,适宜生成ZSM-5/MOR 复合分子筛的条件为钠铝比5~12,晶化温度170~180 ℃、晶化时间48 h;随着钠铝比的增加,ZSM-5 相对结晶度先增加后减少,MOR 相对结晶度一直增加到不变;高钠铝比有利于MOR 的生成,低钠铝比有利于ZSM-5 的
在乙醇溶剂中氢氧化钠与溴化六甲双铵进行交换反应制得高品质的氢氧化六甲双铵,以其为模板剂合成ITQ-13 分子筛,通过XRD、SEM 等表征手段对以不同铝源合成的ITQ-13 分子筛样品的物理化学性能进行了详细的考察。结果表明在此合成系统中硝酸铝和偏铝酸钠为ITQ-13 分子筛合成的最佳铝源。
以HF-TEAOH 为模板剂用水热合成法制备具有CHA 骨架结构的SAPO-34 分子筛,采用XRD、SEM 等手段对分子筛进行表征。以固定床反应装置,对分子筛的MTO 催化活性进行评价。结果表明,采用复合模板剂合成的分子筛具有SAPO-34 结构,并且粒径相比于单独使用TEAOH 模板剂较小。在MTO 反应中双烯选择性在85%以上,与单一模板剂合成的SAPO-34 相比,催化性能较好。
采用两亲的有机硅表面活性剂十八烷基二甲基[3-三甲氧基硅丙基]氯化铵(TPHAC)同时作为部分硅源和介孔模板剂,四乙基氢氧化铵作为微孔模板剂,水热合成出多级孔SAPO-34 分子筛。对样品进行XRD、IR、SEM和N2物理吸附等表征,结果显示合成的SAPO-34 分子筛具有微、介孔复合结构,样品结构中含有TPHAC,TPHAC对SAPO-34 的形貌和多级孔结构的形成具有显著影响。
The electronic structures and the Young’s modulus of the carbon nanotubes doped by nitrogen atoms are studied by means of the self-consistent field crystal orbital method based on density functional t
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