介孔Al2O3负载KF催化剂的制备及其催化性能

Preparation of Mesoporous Alumina Supported KF Catalyst and Its Catalytic Performance for O-Alkylation Reaction of p,p′-Biphenol

通过电中性路径合成了具有大比表面积和窄孔径分布的介孔Al2O3(MA)载体,采用浸渍法制备了MA负载KF新型固体碱催化剂(KF/MA)。对制备的化合物MA及KF/MA催化剂采用XRD、低温N2吸附法、TEM、FTIR和非水系Hammett指示剂法等测试技术进行了表征。所制备的化合物MA具有虫孔状孔道结构,比表面积达375m2/g,平均孔径为7.1nm;负载量为36.7%的KF/MA催化剂碱强度大于18.4,碱量为3.64mmol/g。将KF/MA催化剂应用于4,4′-联苯二酚双甲基化反应,以考察催化剂的催化性能,并与KF/γ-Al2O3催化剂进行了比较。结果表明,KF/MA的催化活性优于KF/γ-Al2O3。原因在于化合物MA较大的比表面积和独特的孔道结构,可以负载更多的KF,并形成有效的表面碱性中心。

Mesoporous alumina （MA） was prepared by a neutral synthesis route. Catalysts （KF/MA） were prepared with MA as support for deposition of potassium fluoride via impregnation. The samples of supports and catalysts were characterized by XRD, N2 adsorption, TEM, FFIR and Hammett titration. The mesoporous alumina samples synthesized by neutral pathway exhibited a wormhole channel motif, and the surface area was 375 m^2/g, and the average pore size was 7.1 nm, and the catalyst possessed a 36.7% KF loading and a basic intensity over 18.4 and a basicity of 3.64 mmol/g. The KF/MA catalysts were employed as highly active/ selective catalysts for the O-alkylation reaction of p, p′-biphenol. The results indicated that the catalytic activity was influenced strongly by the support. The catalytic activity of KF/MA was better than that of KF/γ- Al2O3.