Highly sulfur tolerant and regenerable Pt/CeO2 catalyst for waste to energy

Water-gas shift reaction was applied to upcycle a waste-derived synthesis gas, which contains sulfur as an impurity. Pt/CeO2 was chosen as an appropriate catalyst through a metal and support screening study. The Pt/CeO2 catalyst showed stable catalytic activity without any deactivation for 100 h when the H2S was injected to 100 ppm, and still showed a sulfur tolerance even after 1,000 ppm of H2S was injected. In particular, the catalytic activity was fully regenerated when the H2S injection was stopped, regardless of the H2S concentration. The high sulfur tolerance and regeneration rate of Pt/CeO2 catalyst was due to the high oxygen storage capacity. This accelerates the redox mechanism of the water-gas shift reaction, and also helps the removal of the adsorbed sulfur on the Pt through the oxidation reaction with the mobile oxygen originated from the CeO2.