Effect of Si/O2Al2O3 ratio on the catalytic properties of mordenite for alkylation of biphenyl with propene

Abstract Slurry phase alkylation of biphenyl with propene was carried out using H-mordenite (HM) catalysts with Si/O 2 Al 2 O 3 ratios of 10, 15, and 20. The HM(10) catalyst exhibited low selectivity for 4,4′-diisopropylbiphenyl (4,4′-DIPB) production compared with the HM (20) catalyst. When the external acid sites were posioned by treatment with tributylphosphite, however, HM (10) became the most selective catalyst for 4,4′-DIPB production. The high selectivity of HM (10) was related to its low activity for isomerization of 4,4′-DIPB. Propene was selectively consumed by alkylation on HM (10), while undesirable side reactions of propene occurred on HM (20). These results are understood by taking acid strength into consideration.