摘要
通过向合成ZSM-5分子筛的初始凝胶中加入Fenton试剂作为羟基自由基(·OH)引发剂,在90℃下合成了系列不同晶化时间的超细纳米ZSM-5分子筛(NZ5-Fx)。作为对比,采用传统模板法在170℃下晶化合成了纳米ZSM-5分子筛(NZ5-T)。采用XRD、SEM、TEM、N_(2)物理吸附、^(29)Si MAS NMR、^(27)Al MAS NMR、EPR、NH_(3)-TPD和Py-IR等方法对分子筛进行了表征,并研究了·OH的引入对所合成的NZ5-Fx系列ZSM-5分子筛的物化性质及甲醇制汽油(MTG)催化反应性能的影响。结果表明,与样品NZ5-T相比,·OH促进下低温合成的NZ5-Fx系列ZSM-5分子筛具有更小的晶粒尺寸、更大的介孔孔容,位于孔道交叉处的骨架Al原子所占的比例更高,而且具有更加温和的酸性,在催化MTG反应中表现出更异优的催化性能。以纳米ZSM-5分子筛样品NZ5-F12d为MTG反应的催化剂,甲醇转化率为96.2%时,汽油的选择性高达66.5%。
A series of ultrafine nano-ZSM-5 zeolites(NZ5-Fx)with different crystallization time were synthesized at 90℃by adding Fenton reagent as a hydroxyl radical(·OH)initiator to the initial gel.As a comparison,the nano-ZSM-5 zeolite sample(NZ5-T)was synthesized by traditional template method at 170℃.ZSM-5 zeolites were characterized by XRD,SEM,TEM,N_(2)physical adsorption,^(29)Si MAS NMR,^(27)Al MAS NMR,EPR,NH_(3)-TPD and Py-IR.The effects of the addition of·OH on the physicochemical properties and catalytic performance of ZSM-5 zeolites(NZ5-Fx series of samples)in the methanol to gasoline(MTG)reaction were investigated.The results showed that,compared with sample NZ5-T,NZ5-Fx series of ZSM-5 zeolites synthesized at low temperature under the promotion of·OH had smaller grain size,larger mesopore volume,and higher proportion of framework Al atoms located at the intersection of the channels,and it was more mildly acidity and therefore had better catalytic performance in the MTG reaction.The selectivity for gasoline could reach 66.5%at methanol conversion of 96.2%over the NZ5-F12 d catalyst.
作者
冯超群
苏晓芳
肖林飞
王巍
孟锦滢
吴伟
FENG Chaoqun;SU Xiaofang;XIAO Linfei;WANG Wei;MENG Jinying;WU Wei(School of Chemical and Materials Science,National Center for International Research on Catalytic Technology,Key Laboratory of Functional Inorganic Material Chemistry,Ministry of Education,Heilongjiang University,Harbin 150080,China)
出处
《黑龙江大学自然科学学报》
CAS
2022年第1期78-88,F0003,共12页
Journal of Natural Science of Heilongjiang University
基金
政府间国际科技创新合作重点专项基金资助项目(2018YFE0108800)
国家自然科学基金资助项目(21676074)。
