邻苯二酚与乙醇单醚化反应用固体酸催化剂表面上的积炭行为

 研究了邻苯二酚与乙醇气固相单醚化反应用固体酸催化剂表面上的积炭行为，并用TG－DTA，BET，GC－MS，FT－IR和元素分析等手段对积炭物种进行了表征．结果表明，催化剂上有两种类型的积炭，一类属可溶性积炭，主要由二苯醚及其衍生物组成，可在低温燃烧除去；另一类属不可溶性积炭，主要为缺氢的芳烃类聚合物或类石墨碳，需在高温下才能烧除．积炭主要发生在4～8nm范围的中孔内，导致反应后的催化剂大孔范围的孔分布所占的分数增大．随着反应的进行，总积炭量逐渐增多．

Study on Coke-Deposition Behavior of Solid Acid Catalyst for Vapor Mono-etherification of Catechol

Both guathol ( o ethoxyphenol) and guaiacol ( o methoxyphenol) are the important synthesis intermediates. They were conventionally prepared by liquid phase process. However, generally, the synthetic reactions are extremely expensive, corrosive, toxic and environmental hazardous. Therefore, several solid catalysts have been attempted for selective synthesis of guathol or guaiacol by vapor phase alkylation of catechol, but no investigation focused on the deactivation of the catalysts. In this paper, the coke deposition behavior of the catalyst for vapor mono etherification of catechol was studied using TG DTA, BET, GC MS, FT IR and elementary analysis. The results showed that two kinds of coke exist on the catalyst surface. The soluble coke consists of diphenyl ether and its derivants, it can be eliminated by calcination at lower temperature. The insoluble coke is polymer of aromatic hydrocarbons with hydrogen deficiency or carbon with graphite like structure, their elimination needs higher temperature. Most of soluble coke is adsorbed in mesopores with pore size from 4 to 8 nm, leading to the increase of the fraction of lager pores. The amount of coke increases with increasing reaction time.