Are Noble Metal-Based Water–Gas Shift Catalysts Practical for Automotive Fuel Processing?

Several Pt-based water–gas shift catalysts were prepared and tested for activity and stability. Under feed conditions typical of a reformer outlet, low activity and rapid first-order deactivation were observed. Virtually identical deactivation rates were found for all Pt/ceria water–gas shift catalysts tested. A strong dependence of the deactivation rate on the presence of hydrogen in the feed suggests that a large hydrogen fraction may lead to the irreversible overreduction of the ceria; this problem is likely to plague all such noble metal-based systems.