Robust Au/Ce 0.4 Zr 0.6 O 2 Catalyst for Dynamic Shutdown/Startup of the Water–Gas Shift Reaction in Realistic Reformate with <1 % O 2

Development of a water–gas shift (WGS) catalyst durable in dynamic shutdown/startup operation is essential to enable residential applications of H 2 ‐powered fuel‐cell systems but remains a conundrum for heterogeneous catalysis. We demonstrate herein that by isomorphic substitution of Zr in the lattice of CeO 2 to increase the acid density of the catalyst, complemented by dosing a small amount of O 2 to realistic reformate to improve the oxidizing potential, the formation of the notorious site‐blocking carbonate species on the Au catalyst can be efficiently retarded. This allows the formation of a highly robust Au/Ce 0.4 Zr 0.6 O 2 WGS catalyst suitable for the challenging shutdown/startup operation in realistic reformate.