Oxygen Electroreduction Performance of Ultrasmall Gold Nanoclusters

超小金纳米团簇的电催化氧还原性质（英文）

Ultrasmall gold nanoclusters consisting of 2-4 Au atoms were synthesized and their per- formance in electrocatalytic oxygen reduction reactions （ORR） was examined. These clus- ters were synthesized by exposing AuPPh3Cl to the aqueous ammonia medium for one week. Electrospray ionization mass spectrometry （ESI-MS）, X-ray absorption fihe struc- ture （XAFS）, and X-ray photoelectron spectroscopy （XPS） analyses indicate that the as- synthesized gold clusters （abbreviated as Aux） consist of 2-4 Au atoms coordinated by the triphenylphosphine, hydroxyl, and adsorbed oxygen ligands. A glassy carbon disk electrode loaded with the Aux clusters （Aux/GC） was characterized by the cyclic and linear-sweep voltammetry for ORR. The cyclic voltammogram vs. RHE shows the onset potential of 0.87 V, and the kinetic parameters of JK at 0.47 V and the electron-transfer mmlber per oxygen molecule were calculated to be 14.28 mA/cm2 and 3.96 via the Koutecky-Levich equations, respectively.