八面体骨架分子筛Fe-PKU-1在酯化反应中的应用

Phenyl acetate can be used as raw material as well as an important intermediate in organic synthesis, which can be afforded by esterification reaction of phenol. Fe-PKU-1, a new kind of octahedral molecular sieves with a large number of acidic sites, therefore can participate in the reaction as a new kind of solid acid catalyst. In this paper, Fe-PKU-1 was prepared through the boric acid flux method firstly and then applied to esterification reaction of phenol to test its catalytic activity through univariate method. It showed that solvent, temperature, time and substrates (phenol and acetic anhydride) molar ratio can all perform significant effects on the results. Importantly, Fe-PKU-1 exhibited optimal catalysis performance when phenol/acetic anhydride(1/1.2) were mixed with no solvent in 323 K temperature for 3 h, where the conversion of phenol was 45% and the product selectivity of phenyl acetate could be up to 99%. Furthermore, the thermal stability of Fe-PKU-1 was investigated, the result demonstrated that it still remained definite catalysis performance after five catalytic cycles. Based on the above results, a comprehensive mechanism was proposed. The carbon-oxygen double bond of acetic anhydride is firstly polarized to form a carbocation in the presence of Fe-PKU-1 catalyst, and then the carbocation reacts with the hydroxyl group of phenol to provide phenyl acetate.