シリカーアルミナ系触媒

物理的化学的性質と触媒活性

抄録

Examinations were made on five kinds of synthetic silica-alumina of different manufacturing process, acid clay, and acid-treated white clay as to their physical properties, such as molar ratio of silica to alumina, bulk density, density, surface area, mean granular diameter, pinhole volume, and mean pinhole diameter. The silica-alumina prepared by the coprecipitation method, formed in the high pH-range, possessed larger content of alumina, small surface area, and large average pinhole diameter, while the synthetic silica-alumina prepared by step-precipitation method and acid clay possessed smaller content of alumina, due to the effect of acid treatment, with greater surface area and smaller mean pinhole diameter. Surface acidity of synthetic silica-alumina was determined by the Tamele method to examine the correlationship between the reaction of aniline and methanol, and catalytic activity at the time of preparation of N-methylmorpholine from N-methyl-bis(2-hydroxyethyl) amine. It was thereby found that the acidity determined the ease or difficulty of liberation of the product from catalyst surface, the catalyst of higher acidity increasing the number of methyl groups introduced in the reaction of aniline and methanol, and increasing the rate of decomposition reaction during preparation of N-methylmorpholine.