混合金属络合物羟基镍铝交联蒙托土的表面酸性及催化性能

用NH_3-TPD,IR技术研究了混合金属络合物羟基镍铝交联蒙托土的表面羟基和表面酸性。考察了制备方法、Al/Ni比对其表面酸性的影响,同时用异丙苯裂解反应表征了其催化性能。结果表明,交联蒙托土存在L酸和B酸,其中以L酸为主。表面酸性可能来源于柱子和表面羟基,柱子的热稳定性对表面羟基,表面酸性均有较大影响。Ni的引入增加了L酸和B酸,取代法制备的样品具有比共聚法的样品更强的酸性。交联蒙托土具有较好的异丙苯裂解性能,Ni的引入使其活性有较大的增加。

SURFACE ACIDITY AND CATALYTIC PROPERTIES OF CROSS-LINKED MONTMORILLONITES CONTAINING MIXED-METAL HYDROXY-NI-AI COMPLEXES

The surface hydroxy and surface acidic properties of various cross--linked montmorillonites (CLM) containing hydroxy-Al,Ni,and mixed--metal hydroxy-Ni-Al complexes have been investigated by IR and NH3--TPD.The effect of preparation methods and Al/Ni ratio on the acidic properties and cumene cracking activity of these CLM has been also studied.The results show that the Bronsted and dominant Lewis acid sites are present in CLM.Surface acidity of CLM probably originates from the pillars and its surface hydroxy group.The thermal stabilities of the pillars affect greatly the surface hydroxy and acidity.Bronsted and Lewis acid sites and cumene cracking activities are increased with the introduction of Ni.NiAl-CLM prepared by substitution method has more acid sites than that prepared by co-polymerization method.