Preferential carbon monoxide oxidation (PROX) over Au-based catalyst

Abstract

Preferential CO oxidation (PROX) is the most effective method for removal of CO from the reformate stream. Catalytic activity of Au/CeO2-ZrO2 with various atomic ratios of Ce/ (Ce + Zr) (0, 0.25, 0.5, 0.75, and 1), prepared by the deposition- precipitation method, was investigated in a reformate gas mixture (1% CO, 1% O2, 40% H2, and He) at 50 ℃ to 190 ℃. Catalytic activity depended on the Ce/ (Ce + Zr) atomic ratio. Maximum CO conversion of 94.06% was obtained for 1 w t% Au/Ce0.75Zr0.25O2 at 50 ℃. The effect of H2O in the H2-feed stream was also investigated. The presence of H2O had no significant effect on activity. In the stability test, the activity of both 1 w t% Au/CeO2 and 1 w t% Au/Ce0.75Zr0.25O2 catalysts were maintained in the simulated dry condition at 110 ℃ for 28 h.