The role of manganese contained zeolite catalysts in tuning Bi-/mono-molecular reaction pathway selectivity in FCC process

The gasoline quality of FCC process, especially olefin content, heavily depends on the catalyst performance in terms of bi-/mono-molecular reaction pathway selectivity. A reliable experimental protocol has been established by using m-xylene as a probe molecule to clarify the selectivity based on detailed reaction chemistry of m-xylene including the consecutive bi-molecular disproportionation and isomerization. Another pure hydrocarbon, n-dodecane, has been used as probe molecule to characterize the selective hydrogen transfer ability of catalytic materials. A novel series of FCC catalysts has been developed aiming at gasoline olefin reduction based on manganese incorporation or modification. The role of manganese in tuning bi/mono-molecular reaction pathway selectivity and hydrogen transfer selectivity in FCC process is elucidated by experimental approaches described. The results have been correlated with the practical performance of the new catalysts.