Future refinery feedstocks will include greater portions of residual oils which contain high amounts of nickel and vanadium compounds. These metals are poisons for hydrodesulfurization and cracking catalysts. Deposition of the metals on the catalyst surface occurs via hydrodemetallation reactions; plugging of pores and changes in catalytic activity and selectivity result. The kinetics of metal deposition on various catalysts has been examined, but characterization of the interaction of the organometallic compounds with the catalyst has not been extensive. Our results indicate that resonance Raman spectroscopy is a very effective method for examining trace contaminants of nickel and vanadium porphyrins on γ-Al2O3.
B. J. Streusand and G. L. Schrader, "Resonance Raman Spectra of Porphyrins on Gamma-Alumina and Silica," Appl. Spectrosc. 38, 433-435 (1984)