The effect of modifying group on the acid properties and catalytic performance of sulfonated mesoporous polydivinylbenzene solid acid in the Bisphenol-A synthesis reaction

Abstract

A series of sulfonated mesoporous polydivinylbenzene solid acids were prepared with various ways. The effect of sulfonation method and modifying group on the acid properties and catalytic performance of these solid acids was studied with the synthesis of Bisphenol-A as a probe reaction. The characterization results revealed that post sulfonation method was beneficial for grafting more sulfonic acid groups to improve the acid densities of sulfonated mesoporous polydivinylbenzene solid acids. In particular, for sulfonated mesoporous polydivinylbenzene modified by different groups, the electron withdrawing groups could enhance the acid strength of sulfonated mesoporous polydivinylbenzene. Then the strong acid sites not only had high catalytic efficiency but also were beneficial for producing target product Bisphenol-A to improve the selectivity. Trifluoromethanesulfonyl modifying sulfonated mesoporous polydivinylbenzene solid acid (PDVB-SO2CF3-SO3H) had the strongest acidity and optimal catalytic behavior. The phenol conversion of 36% (phenol theoretical conversion of 40%) and the Bisphenol-A selectivity of 90% were obtained at 90 °C for 4 h. In addition, PDVB-SO2CF3-SO3H had excellent reusability and could be reused at least 6 times. This work highlighted the effect of modifying groups with different electronic effects on the acidity of the sulfonated mesoporous polydivinylbenzene, and provided methods and references for regulating the acidity of other polymer solid acids.