Atomically dispersed Au anchored on CeO 2 to enhancing the antioxidant activity.

The modification of Au nanoparticles can improve the antioxidant activity of CeO 2 , however, nano Au/CeO 2 has also met some problems such as low atomic utilization, the limit of reaction conditions, and high cost. Au single atom catalysts can well solve the above-mentioned problems, but there are some contradictory results about the activity of single atom Au 1 /CeO 2 and nano Au/CeO 2 . Here, we synthesized rod-like Au single atom Au/CeO 2 (0.4% Au 1 /CeO 2 ) and nano Au/CeO 2 (1% Au/CeO 2 , 2% Au/CeO 2 and 4% Au/CeO 2 ), and their antioxidant activity from strong to weak is 0.4% Au 1 /CeO 2 , 1% Au/CeO 2 , 2% Au/CeO 2 and 4% Au/CeO 2 , respectively. The higher antioxidant activity of 0.4% Au 1 /CeO 2 is mainly due to the high Au atomic utilization ratio and the stronger charge transfer between Au single atoms and CeO 2 , resulting in the higher content of Ce 3+ . Due to the coexistence of Au single atoms and Au NPs in 2% Au/CeO 2 , the antioxidant activity 2% Au/CeO 2 is higher than that of 4% Au/CeO 2 . And the enhancement effect of Au single atoms was not affected by the concentration of ·OH and material concentration. These results can promote the understanding of the antioxidant activity of 0.4% Au 1 /CeO 2 and promote its application.