Abstract:

Different NaY molecular sieves, including NaY, HY, USY and Ce-USY, were prepared by in situ hydrothermal process, ion exchange and/or hydrothermal treatment. The effects of isologous Y molecular sieves on p-aminophenol preparation from phenyl-hydroxylamine rearrangement were studied. XRD, N₂ adsorptiondesorption and Py-FTIR results showed that although the molecular sieves had differences in crystallinity, they all had the skeleton topology of Y type molecular sieves. The micropore size of HY molecular sieve was about 0.58 nm. NaY molecular sieve had almost no B acid site. For three kinds of other molecular sieves, B acid content ranked in the descending sequence: HY>USY≈Ce-USY, and L acid content ranked in the descending sequence: USY≈Ce-USY>HY. The performance of their catalysts showed that Y-type molecular sieve had the inferior performance, the selectivity and yield of p-aminophenol of target product were less than 15%. So the p-aminophenol product with high yield and purity could be prepared from the smallest amount of reactant only when molecular sieve maintained an appropriate amount of acidity and pore size.

Key words: Y zeolite, Acidity, Bambenger rearrangement, p-Aminophenol, Selective

摘要： 采用水热合成法制备了NaY分子筛，经离子交换和水热处理制得HY、USY和 Ce-USY。研究了不同类型的Y分子筛对催化苯基羟胺重排合成对氨基苯酚的影响。XRD、N2吸附和Py-FTIR表征结果表明，此系分子筛虽然结晶性有差异，但均具有Y型分子筛的骨架拓扑结构。HY分子筛微孔孔径约为0.58 nm。NaY分子筛几乎无B酸中心。对其他3种分子筛而言，B酸量大小为：HY>USY≈Ce-USY；L酸量大小为：USY≈Ce-USY>HY。催化反应结果表明，Y型分子筛在此反应中表现出较差的效果，目标产物对氨基苯酚选择性和收率均低于15.00%。可见分子筛需维持酸性和孔径大小恰当时，才能使用最少的原料得到收率和纯度都较高的对氨基苯酚。

关键词: Y型分子筛, 酸性, Bambenger重排, 对氨基苯酚, 选择性