Electrochemical Observation of High Oxophilicity and its Effect on Oxygen Reduction Reaction Activity of Au Clusters Mass-Selectively Deposited on Glassy Carbon

摘要

The measurement procedure of oxophilicity and electrocatalytic activity for oxygen reduction reaction (ORR) on size-selected Au clusters was developed and applied. Mass-selected Au~(9)clusters were deposited on a glassy carbon substrate under ultrahigh vacuum (UHV) conditions, and the model electrode was transferred to an electrochemical cell with the rotating disk electrode (RDE) configuration. Cyclic voltammetry exhibited a significantly lower oxide-reduction peak potential of the Au clusters than that of bulk Au in the first cycle, thus confirming the exceptionally higher oxophilicities for the former. After performing cyclic voltammetry with an upper limit potential of 1.8?V versus a reversible hydrogen electrode, the ORR activity of the Au clusters was lower than that of bulk Au and bulk Pt. This result was partially ascribed to aggregations of Au clusters during the potential cycles. Graphical Abstract ?.