Hollow mesoporous CeO2 microspheres for efficient loading of Au single-atoms to catalyze the water-gas shift reaction

The atomically dispersed catalysts have aroused great attention in the recent decade. However, the preparation of atomically dispersed Au catalysts presents more challenge than other atomically dispersed catalysts such as Pt, Pd, etc. From the aspect of support, this work contributes a novel hollow mesoporous CeO 2 microspheres (CeO 2 -hm) for efficient dispersion of single Au atoms (Au 1 ). Contributed by the high specific surface area and mesoporous structure, CeO 2 -hm possesses much higher capacity for undertaking Au 1 , than commercial CeO 2 particles (CeO 2 -c). Typically, with Au loading of 0.2 at%, CeO 2 -hm supported Au (Au 1 /CeO 2 -hm) presents atomic dispersion while CeO 2 -c supported Au (Au/CeO 2 -c) contains large amount of Au nanoparticles . Confirmed by catalyzing the water-gas shift (WGS) reaction, the obtained Au 1 /CeO 2 catalysts exhibit notably higher performance than the Au-based catalysts supported by CeO 2 -c and CeO 2 synthesized through co-precipitation and sol-gel strategies. For example, 0.2 at% Au 1 /CeO 2 -hm exhibits 9.1 times reactivity of equal Au loaded Au/CeO 2 -c catalyst. Besides, the CeO 2 -hm supported single-atom Au catalyst presents good tolerance under long-time WGS running.