Isopropylation of biphenyl over ZSM-12 zeolites

摘要: Abstract ZSM-12 zeolites, ZSM-12L and ZSM-12S, with MTW topology were synthesized by using methyltriethylammonium bromide (MTEABr) tetraethylammnoium (TEABr) as structure directing agents (SDA), respectively, for the isopropylation of biphenyl (BP) propene an alkylating agent. The particle sizes ZSM-12S in range 5–10 μm less than 0.5 μm, respectively. selectivities 4,4′-diisopropylbiphenyl (4,4′-DIPB) 60–70% 40–50% at lower temperatures below 275 °C, rapidly decreased further increase to 20% 350 °C over both zeolites. kinetic controlled catalyses on external acid sites resulted formation bulkier isomers, 2,x′-DIPB (x:2,3,4). decreases selectivity 4,4′-DIPB occurred isomerization stable 3,4′- 3,3′-DIPB higher temperatures. These remarkably ZSM-12LD prepared dealumination EDTA-3Na, because effective removal sites. BP zeolites was moderately shape-selective appropriate temperatures, particularly ZSM-12LD. primarily near pore-entrances but not deep channels. channels are selective MOR