Transalkylation of diisopropylbenzenes with benzene over hierarchical beta zeolite

The hierarchical beta zeolite has better activity compared with the conventional beta zeolite for the transalkylation of diisopropylbenzene with benzene. By studying the effects of pore structure, crystal size and acidity on catalytic activity, one finds that the better activity of the hierarchical beta zeolite is mainly due to the presence of meso/macropores and nanocrystals. The catalytic performance of the hierarchical beta zeolite prepared via the dry gel conversion method was compared with that of the conventional beta zeolite for transalkylation of diisopropylbenzene with benzene. The results indicate that diisopropylbenzene conversion decreases from 74% to 29% after a reaction time of 32 h over the conventional beta zeolite. However, for the hierarchical beta zeolite, diisopropylbenzene conversion still remains above 60% after 32 h under the same reaction conditions. In order to learn the factors leading to the difference in catalytic activity, we studied pore structure, crystal size and acidity of the hierarchical beta zeolite and the conventional beta zeolite and we discussed their effects on catalytic activity. The results reveal that the better activity and stability of the hierarchical beta zeolite is mainly due to the presence of meso/macropores and nanocrystals for the liquid transalkylation reaction.