Highly stable Co/CeO2 catalyst for high-temperature water–gas shift reaction using a CeO2 support with an optimized precipitant ratio

Abstract

We report hydrogen production from waste through waste gasification and the water–gas shift reaction using highly stable Co/CeO₂ catalysts. Here, careful control of the KOH:K₂CO₃ precipitant ratio during CeO₂ support synthesis yielded highly active and stable Co/CeO₂ catalysts. Crucially, the precipitant ratio affects the Co dispersion, oxygen vacancies, crystallinity, and Co-CeO₂ interactions, and the Co dispersion increases with increase in KOH content. Further, the oxygen storage capacity improves at the optimal KOH:K₂CO₃ ratio. In addition, the Co-CeO₂ interaction is enhanced when catalysts are synthesized using CeO₂ with a large amount of K₂CO₃. All prepared Co/CeO₂ catalysts show high CO conversion, even at extremely high gas hourly space velocities: the Co/CeO₂ (λ = 2:1 and 1:1.5) catalysts exhibit stable performance because of robust Co-CeO₂ interactions, high oxygen storage capacities, and effective Co dispersions. These findings aid hydrogen production from waste and CeO₂ support design for various catalytic reactions.