Synthesis of micro-mesoporous molecular sieve ZSM-5/SBA-15: tuning aluminium content for tert-butylation of phenol

Abstract

Micro-mesoporous ZSM-5/SBA-15 molecular sieve was derived from mesoporous molecular sieves SBA-15 by hydrothermal crystallization approach. The silica-alumina ratio significantly affects the structure and catalytic performance of ZSM-5/SBA-15. When the $$\hbox {n}_{\mathrm{Si}}\hbox {/n}_{\mathrm{Al}}$$ is less than 25, the two-dimensional hexagonal pore structure of SBA-15 keeps intact with relatively low crystallinity of the pore wall. However, when the $$\hbox {n}_{\mathrm{Si}}\hbox {/n}_{\mathrm{Al}}$$ is larger than 50, the SBA-15 pores are severely damaged. When $$\hbox {n}_{\mathrm{Si}}\hbox {/n}_{\mathrm{Al}}$$ is 25, the catalyst ZSM-5/SBA-15 retains relatively good pore structure and shows excellent catalytic performance with 96.2% phenol conversion and 53.5% selectivity to 2,4-ditert-butyl phenol in the tert-butylation of phenol. SYNOPSIS Micro-mesoporous ZSM-5/SBA-15 molecular sieve was derived from mesoporous molecular sieve SBA-15 by hydrothermal crystallization approach. ZSM-5/SBA-15 ( $$\hbox {n}_{\mathrm{Si}}\hbox {/n}_{\mathrm{Al}}=25$$ ) retains relatively good pore structure and shows excellent catalytic performance with 96.2% phenol conversion and 53.5% selectivity to 2,4-ditert-butyl phenol in the tert-butylation of phenol. Effect of silica-alumina ratio of micro-mesoporous silica ZSM-5/SBA-15 on the catalytic performance of tert-butylation of phenol