PHOSPHORUS MODIFIED ZEOLITE CATALYSTS

摘要

An unbound catalyst composition comprises a zeolite and phosphorus in an amount between about 0.01 wt% and about 3 wt% of the total catalyst composition. The catalyst composition, as calcined at ~1000°F (~538°C) for at least -3 hours, can exhibit (i) 2,2- dimethylbutane diffusivity >1.5 x 10-2 sec-1 when measured at ~120°C and ~60 torr (~8 kPa), (ii) coke deactivation rate constant <~0.15, and (iii) alpha value at least 10, and further exhibiting at least one of: (a) mesoporosity >0.2 ml/g; (b) microporous surface area at least 375 m2/g; and (c) coke deactivation rate constant <0.05 after steaming in ~100% steam tor~96 hours at ~1000°F (~538°C).