Abstract: Hierarchical pore ZSM-5 molecular sieves are prepared by salt-added crystal seed induced route in a micro-impinging stream reactor (MISR).The effects of colloidal silica flow rate,flow rate of crystal seed-containing natrium aluminate mixture,cycle time and crystallization time on the particle and pore sizes of ZSM-5 molecular sieves are investigated.The prepared ZSM-5 molecular sieves are compared with its same kind catalysts synthesized by traditional method in the aspects of catalytic activity,selectivity and reaction temperature through their applications in the benzylation of toluene by benzyl chloride.The optimal operating parameters for synthesis of hierarchical pore ZSM-5 molecular sieves by micro-impinging stream strengthened mixing process are obtained as follows:40 mL·min-1 for the flow rate of colloidal silica,20 L·h-1 for the flow rate of crystal seed-containing natrium aluminate mixture,5 min for the cycle time and 6 h for the time of crystallization.The experimental results of the benzylation of toluene by benzyl chloride show that the conversion of benzyl chloride increases with temperature,and the catalytic activity and selectivity of the hierarchical pore ZSM-5 molecular sieves prepared by MISR is better than that of the ones prepared by traditional method.
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