Fe2O3催化甲基化合成2，3，5-三甲基苯酚

制备并考察了甲醇甲基化法合成2，3，5-三甲基苯酚的固体酸催化剂，进行了甲基化反应工艺条件的优化研究。实验结果表明，最优工艺条件：反应温度370 ℃、液空速0.2 h^-1、n(3，5-二甲基苯酚)∶n(甲醇)∶n(水)=1∶2∶1；原料3，5-二甲基苯酚的转化率达95.96％，目的产物2，3，5-三甲基苯酚的收率为72.01％。并采用XRD、SEM、DTA和TG等测定方法对催化剂进行了研究，发现催化剂表面上积炭污染是造成催化剂活性下降的主要原因。

Vapor phase synthesis of 2,3,5-trimethyl phenol over iron catalyst and deactivation of the catalyst

Vapor phase synthesis of 2,3,5-trimethyl phenol from methanol and 3,5-dimethyl-phenol over solid acid catalyst was studied in a fixed bed reactor. Effects of temperature, molar ratio of the feed (3,5-dimethyl-phenol, methanol and water) and space velocity were investigated. The optimum process condition was as follows：reaction temperature 370 ℃, space velocity 0.2 h^－1, and n(3,5-dimethyl phenol)∶n(methanol) ∶n(water)=1∶2∶1. 3,5-dimethyl-phenol conversion of 95.96％ and 2,3,5-trimethyl phenol yield of 72.01% was obtained under the optimal condition. The catalyst was characterized by XRD, DTA, TG and SEM techniques. The results showed that coke formation was the main cause for catalyst deactivation.