Shape-Selective Synthesis of 4,4'-Dimethylbiphenyl over Nanoporous Acidic Catalysts

摘要

Shape-selective alkylation of polycyclic hydrocarbons in preparation of symmetric intermediates such as 4,4'-dialkylbiphenyl (4,4'-DABP) or 2,6-dialkylnaphthalene (2,6-DAN), the important precursors for advanced polymer materials, has been the focus on many recent studies. As for alkylation preparation of 4,4'-DABP, the alkylation can be carried out using either the large group like isopropyl or the small one such as ethyl and methyl groups. Like isopropylation of naphthalene and its derivates into 2,6-DAN, the alkylation of BP and its derivates can also achieve high selectivity over dealuminated mordenite, however, it is extremely difficult to selectively obtain 4,4'-dimethylbiphenyl through methylation of BP and its derivates. Recently, some breakthrough on methylation of 4-methylbiphenyl with methanol was achieved in which Dr Shen et al achieved the selectivity as high as 65% over HZSM-5 modified with inorganic P compound. With these encouraging findings and knowledge, in this paper we further investigated the methylation of 4-MBP with methanol over nanoporous acidic catalysts and correlated the physical properties with catalytic reaction.