Sour water-gas shift reaction over Pt/CeZrO2 catalysts

The influence of H2S on the performance of platinum catalysts for the water-gas shift reaction was investigated. Platinum catalysts supported on different oxides (gamma-Al2O3, ZrO2, CeO2, Ce0.75Zr0.25O2, and Ce0.25Zr0.75O2) were tested under industrial conditions in the absence and presence of H2S. Pt/CeO2 showed higher initial catalytic activity than Pt/Al2O3, but exhibited some deactivation and low recovery of catalytic activity when subjected to contaminated conditions, due to the formation of sulfur species on the ceria surface. Zirconia addition to CeO2 was beneficial to increase sulfur tolerance and preserve high activity. The deactivation ratios for Pt/CeZrO2 catalysts were very close and recovery ratios were 100%, indicating that for these catalysts the deactivation is reversible, which can be related to less interaction between H2S and these supports. (C) 2016 Elsevier Inc. All rights reserved.