LAUSR

The modification of Au nanoparticles can improve the antioxidant activity of CeO2, however, nano Au/CeO2 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 Au1/CeO2 and nano Au/CeO2. Here, we synthesized rod-like Au single atom Au/CeO2 (0.4% Au1/CeO2) and nano Au/CeO2 (1% Au/CeO2, 2% Au/CeO2 and 4% Au/CeO2), and their antioxidant activity from strong to weak is 0.4% Au1/CeO2, 1% Au/CeO2, 2% Au/CeO2 and 4% Au/CeO2, respectively. The higher antioxidant activity of 0.4% Au1/CeO2 is mainly due to the high Au atomic utilization ratio and the stronger charge transfer between Au single atoms and CeO2, resulting in the higher content of Ce3+. Due to the coexistence of Au single atoms and Au NPs in 2% Au/CeO2, the antioxidant activity 2% Au/CeO2 is higher than that of 4% Au/CeO2. 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% Au1/CeO2 and promote its application.