TiCl4改性离子交换树脂催化合成甲缩醛

大孔阳离子交换树脂的磺酸基团与TiCl4络合，形成新的不会被阳离子交换而失活的Lewis酸中心。本文采用液固溶剂法制备金属改性离子交换树脂催化剂，应用于合成甲缩醛反应体系。实验考察了TiCl4负载量、负载温度和负载时间等工艺条件对催化活性的影响，通过正交实验获得了催化剂的较佳制备条件。研究结果显示，经TiCl4负载改性后的阳离子交换树脂的ggwis酸中心大幅度降低，催化活性显著提高。在相同实验条件下，合成甲缩醛的反应收率比改性前最大提高了13．5％，催化剂重复使用6次，催化活性无明显降低。

Synthesis of Methylal Catalyzed by TiCl4 Modified Cation Exchange Resin

A type Lewis acid center is formed onto surface of cation exchange resin by reaction titanium tetrachloride （TICl4 ） with sulfonic group. According to this reaction mechanism, a kind catalyst of TICl4 modified cation exchange resin was prepared, used for catalytic synthesis of methylal. The influence of the preparation conditions on the catalytic activity, including immobilization temperature, reaction period time and the mass ratio of TICl4 to cation exchange resin was investigated. With using the producing rate of methylal as the technical index, the optimum preparation parameters of the catalyst were obtained through orthogonal test method of experimental arrangement. The experimental results indicated that the catalysts prepared had strong Lewis acidity and higher catalytic activity on synthesis of methylal, for yield of the product was increased by 13.5% than that of no modified cation exchange resin as the catalyst.