以共缩合方法制备了一系列苯磺酸修饰的层柱磷酸锆材料,利用N2吸附/脱附、Si核磁共振、红外光谱和热重分析等方法对其结构进行了表征.将其应用于对苯二酚与叔丁醇烷基化反应,研究结果表明,催化剂合成时的投料比对其催化性能有较大的影响,催化剂ZrP-0.4-2-10%-PhSO3H的催化性能最佳,反应4 h,对苯二酚的转化率为85.4%,2-叔丁基对苯二酚产率达到58.5%.酸性表征结果表明,催化剂活性与其表面可接触酸性位的数目密切有关.该催化剂还具有较好的重复利用性能,反应3次后产物产率仅下降10%.催化剂失活是由于磺酸基团的脱落或活性位被积碳覆盖所引起的.
A series of phenylsulfonic acid functionalized porous phosphate heterostructure(PPH) materials were prepared by co-condensation method and characterized by SEM,FTIR,29Si MAS NMR,TG and N2 adsorption.Their catalytic behavior for alkylation of hydroquinone with tert-butanol was compared.The catalytic activity was greatly enhanced after the introduction of phenylsulfonic acid group.ZrP-0.4-2-10%-PhSO3H is a more active catalyst for the reaction in comparison to others.The conversion of hydroquinone and the yield of 2-tert-butylhydroquinone on the catalyst reach 85.4% and 58.5% at 150 ℃,respectively.The activity correlates well with the amount of the accessible acid sites on its surface.The catalyst is stable and reusable,and the product yield is only reduced by 10% after three runs.The reduction in activity is probably caused by leaching of phenylsulfonic group or deposition of coke on the active sites.