X-ray Absorption Study of Vanadium in Fluid Cracking Catalysts

Development of heavy metal passivators in residue fluid catalytic cracking process

“…For steaming catalysts exposed to V by physical mixing or impregnation, X-ray absorption spectroscopy (XAS) experiments discovered that the V adsorption edges were similar, showing the same coordination geometry and oxidation state [44]. Following steam treatment, vanadium was found to be dispersed throughout the catalyst particle, according to electron microprobe investigations.…”

X-Ray absorption and photoelectron spectroscopic investigation of vanadium interaction with NH4+- and Eu3+-exchanged zeolite-Y following calcination and steam treatment

“…Vanadium, in addition, reduces catalytic activity and selectivity by destroying the crystallinity of the zeolite. 14 The interaction of vanadium with zeolite-Y and, in particular, the mechanism by which the crystallinity of the zeolite is destroyed, has been the subject of a number of investigations, [5][6][7][8][9][14][15][16] although no overall consensus has been reached on the details of the processes involved. In recent work, Trujillo et al, 14 in agreement with the earlier work of Pine, 15 have proposed that vanadium, in the form of vanadic acid, is involved in the destruction of the zeolite structure by framework hydrolysis.…”