Micro-mesoporous ZSM-5/SBA-15 molecular sievewas 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 nSi/nAl 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 nSi/nAl is larger than 50, the SBA-15 pores are severely damaged. When nSi/nAl is 25, the catalyst ZSM-5/SBA-15 retainsrelatively 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.
