Nickel and vanadium on equilibrium cracking catalysts by imaging secondary ion mass spectrometry

Abstract

The distribution of nickel and vanadium has been determined on refinery samples of several types of fluidized catalytic cracking catalyst. Data from imaging secondary ion mass spectrometry show that metals in catalytic cracking feedstocks initially deposit near the external surface of catalyst particles. Nickel remains in the area where it was deposited, while vanadium shows both intraparticle and interparticle mobility. Vanadium accumulates throughout catalyst particles, but shows a preference for both rare earth exchanged Y-zeolite and alumina phases in composite catalyst. By contrast, nickel shows no preference for catalyst phases and accumulates monotonically with time. The lack of mobility in deposited nickel makes it a good measure to determine the age of individual particles.