摘要
考察了晶化温度、模板剂用量、硅铝比和搅拌等条件对 MCM-22分子筛结晶性的影响,并采用X射线衍射(XRD)、电感耦合等离子体发射光谱(ICP-AES)、氮吸附和氨气-程序升温脱附(NH_3-TPD)等对分子筛样品进行表征。结果表明,在135℃,模板剂六亚甲基亚胺与 SiO_2的物质的量之比为0.75和硅铝比(SiO_2与 Al_2O_3的物质的量之比)为120的条件下,合成出纯相的 MCM-22分子筛。将合成的分子筛样品作为甲醇脱水催化剂与甲醇合成催化剂混合用于合成气一步法制二甲醚,发现高硅 MCM-22分子筛是良好的一步法制二甲醚脱水催化剂,二甲醚选择性达到67%以上,副产物二氧化碳和烃类选择性仅为29%和0.07%。
Effects of crystallization temperaure, dosage of structure directing agent, molar ratio of SiO2 to Al2O3 and agitation on crystallization of MCM-22 molecular sieves were investigated and the molecular sieves were characterized by methods of X-ray diffraction （XRD）, inductively coupled plasma-atomic emission spectrometry （ICP-AES）, nitrogen adsorption and ammonia temperature programmed desorption （NH3-TPD）. The results showed that the pure MCM-22 molecular sieves were synthesized under the conditions of 135℃, moalr ratio of hexamethyleneimine （HMI） to SiO2 0.75 and moalr ratio of SiO2 to A1203 120. The MCM-22 molecular sieves, as methanol dehydration catalysts, were mechanically mixed with methanol synthesis catalysts to catalyze one-step synthesis of dimethyl ether from syngas. Over the MCM-22 molecular sieves with high molar ratio of SiO2 to Al2O3, the selectivities of dimethyl ether, CO2 and hydrocarbons were 67%, 29% and 0.07% respectively.
出处
《化学反应工程与工艺》
EI
CAS
CSCD
北大核心
2008年第4期337-341,共5页
Chemical Reaction Engineering and Technology
