杂原子硼对Y型分子筛性能的影响

利用X射线粉末衍射、差示扫描量热、NH3吸附-程序升温脱附、吡啶吸附红外光谱等方法考察了硼原子进入Y型分子筛骨架后对分子筛的晶型、晶胞参数、热稳定性、水热稳定性以及表面酸性的影响。实验结果表明,由于硼原子进入Y型分子筛的骨架,使其晶胞收缩,但不影响分子筛的晶型,分子筛的结晶度随硼加入量的增加而先增大后减小;分子筛的热稳定性及水热稳定性有所下降;分子筛表面的酸性质发生变化,其中B酸中心数量明显增加。

Effect of Hetero - Atom B on the Performances of Y Molecular Sieves

BY molecular sieves was synthesized in process of hydrothermal synthesis of Y molecular sieves.The changes brought about to Y molecular sieves,after entering of B into crystalline framework of it,was characterized by XRD,DSC,NH_3-adsorption and pyridine-IR methods.The entering of B did not change the crystalline form,but caused the contraction of crystal cell parameter.The crystallinity of Y molecular sieves increased along with the B content,approached to a maximum then fell.The heat stability and hydrothermal stability of BY molecular sieves decreased.The surface acidity changed,especially those of the strong Bronsted acid sites obviously increased.