A well defined Au38(SR)24/CeO2 nanocatalyst is studied for CO oxidation.
La, Y, Ga, and Sm are doped into CeO2 to modulate the Ce4+/Ce3+ ratio.
Increasing the Ce4+/Ce3+ ratio increases the catalyst activity.
The rate limiting step is identified to be the coordination of lattice oxygen to CO which itself is coordinated by the gold nanocluster.