Elucidating the effect of Ce/Zr ratio on high temperature shift activity with sulfur poisoning

Abstract

To elucidate the effect of CeO2/ZrO2 ratio on the sulfur-tolerance in high temperature shift using waste derived synthesis gas, the Ce/Zr ratio in Pt/CexZr1-xO2 catalysts was systematically changed. Pt/CexZr1-xO2 catalysts were applied to the high temperature shift reaction with 500 ppm H2S. In the presence of H2S, the catalysts were deactivated with time on stream due to the poisioning of H2S. Sulfur-tolerance in high temperature shift activity depended upon the oxygen storage capacity of the catalysts. The regeneration rate of the catalysts was also related with the oxygen storage capacity. In addition, the Pt dispersion matched the oxygen storage capacity trend. The oxygen storage capacity is a main function to determine the sulfur tolerance in high temperature shift activity compared to the dispersion of Pt.