Aluminosilicate zeolites as one of the most important catalytic materials are widely applied in industrial reactions,and understanding of their synthetic mechanism is one of key factors in this field.27Al and 29Si NMR...Aluminosilicate zeolites as one of the most important catalytic materials are widely applied in industrial reactions,and understanding of their synthetic mechanism is one of key factors in this field.27Al and 29Si NMR techniques are one of powerful tools for characterization of zeolite synthesis,but unfortunately the study on 27Al NMR spectra of aluminosilicate solutions is still argumentative,and the assignment of aluminosi-licate species in the solutions are challengeable.In this work,we have carefully compared 27Al NMR spectra of various aluminosilicate solutions,harmonizing the assignments reported previously.Furthermore,we assigned 29Si NMR spectra related to Al species.The peaks at δ:-75.1 and-82.5 in 29Si NMR spectrum are related to Q2 Al species,the peaks at δ:-84.5 and-90.8 are related to Q3 and Q4 Al species in aluminosilicate solutions,respectively.展开更多
提出了应用高效NaY沸石导向剂快速合成A型沸石的新方法.在合成过程中,NaY沸石导向剂提供了全部硅源(无需另加硅源).与用水玻璃提供硅源的合成方法相比,该法晶化速度快,合成温度低,并可在低碱度条件下合成超细A型沸石.29S i NMR表征和UV ...提出了应用高效NaY沸石导向剂快速合成A型沸石的新方法.在合成过程中,NaY沸石导向剂提供了全部硅源(无需另加硅源).与用水玻璃提供硅源的合成方法相比,该法晶化速度快,合成温度低,并可在低碱度条件下合成超细A型沸石.29S i NMR表征和UV Ram an研究表明,高效NaY沸石导向剂中含有大量的六元环等低分子量硅铝酸根前驱体,它们有利于A型沸石成核与晶体生长.展开更多
在水热条件下改变合成参数合成了系列SAPO-11分子筛，采用XRD和^29Si MAS NMR等手段对样品进行表征，并考察了合成参数对SAPO-11分子筛性能的影响。结果表明，合成条件对SAPO-11分子筛的骨架Si分布有很大影响。延长晶化时间、升高晶化...在水热条件下改变合成参数合成了系列SAPO-11分子筛，采用XRD和^29Si MAS NMR等手段对样品进行表征，并考察了合成参数对SAPO-11分子筛性能的影响。结果表明，合成条件对SAPO-11分子筛的骨架Si分布有很大影响。延长晶化时间、升高晶化温度、降低硅／铝比（n（SiO2）／n（Al2O3））或控制初始溶胶pH值为5．0～5．4都可以促进骨架Si的均匀分布，得到具有较高Si分散度的SAPO-11分子筛。展开更多
文摘Aluminosilicate zeolites as one of the most important catalytic materials are widely applied in industrial reactions,and understanding of their synthetic mechanism is one of key factors in this field.27Al and 29Si NMR techniques are one of powerful tools for characterization of zeolite synthesis,but unfortunately the study on 27Al NMR spectra of aluminosilicate solutions is still argumentative,and the assignment of aluminosi-licate species in the solutions are challengeable.In this work,we have carefully compared 27Al NMR spectra of various aluminosilicate solutions,harmonizing the assignments reported previously.Furthermore,we assigned 29Si NMR spectra related to Al species.The peaks at δ:-75.1 and-82.5 in 29Si NMR spectrum are related to Q2 Al species,the peaks at δ:-84.5 and-90.8 are related to Q3 and Q4 Al species in aluminosilicate solutions,respectively.
文摘提出了应用高效NaY沸石导向剂快速合成A型沸石的新方法.在合成过程中,NaY沸石导向剂提供了全部硅源(无需另加硅源).与用水玻璃提供硅源的合成方法相比,该法晶化速度快,合成温度低,并可在低碱度条件下合成超细A型沸石.29S i NMR表征和UV Ram an研究表明,高效NaY沸石导向剂中含有大量的六元环等低分子量硅铝酸根前驱体,它们有利于A型沸石成核与晶体生长.
文摘在水热条件下改变合成参数合成了系列SAPO-11分子筛，采用XRD和^29Si MAS NMR等手段对样品进行表征，并考察了合成参数对SAPO-11分子筛性能的影响。结果表明，合成条件对SAPO-11分子筛的骨架Si分布有很大影响。延长晶化时间、升高晶化温度、降低硅／铝比（n（SiO2）／n（Al2O3））或控制初始溶胶pH值为5．0～5．4都可以促进骨架Si的均匀分布，得到具有较高Si分散度的SAPO-11分子筛。
