Deactivation of External Acid Sites of H-Mordenite with Ceria Modification in the Isopropylation of Biphenyl.

Cerium modification of H-mordenite was highly effective for the deactivation of acid sites on external surfaces in the isopropylation of biphenyl. The selectivity for 4,4'-diisopropylbiphenyl (4,4'-DIPB) over unmodified H-mordenite decreased with the increase of reaction temperature because of the isomerization of 4,4'-DIPB at the external acid sites. The isomerization was effectively prevented by the ceria modification of H-mordenites.