Atomically precise gold and/or silver nanoclusters play a key role in crystallography and coordination chemistry.Compared with gold nanoclusters,silver nanoclusters become unstable and difficult to crystal-lize due to the high reactivity of metal silver.Herein,we report a silver nanocluster Ag213(Adm-S)44Cl33(Ag213)coprotected by bulky thiolates and chlorides.The low surface thiolate coverage(about 45％)endows Ag213 with high catalytic activity.Supported on activated carbon,Ag213 nanoclusters exhibit excellent electro-catalytic oxygen reduction performance with Eonset and E1/2 values of 0.89 and 0.72 V,respectively,close to the values of commercial Pt/C catalyst.This is the first report on the electrocatalytic oxygen reduction reaction of nanoclusters with more than 100 silver atoms.Ag213 with the diameter of 2.75 nm comprises a core-shell structure Ag7@Ag32@Ag77@Ag97.The strong plasmonic absorption band at 454 nm reveals the metallic nature of Ag213.Interestingly,halide is of importance.Chloride facilitates the formation of Ag213 and Ag56(Adm-S)33CI16(Ag56Cl)while bromide can promote the formation of Ag56(Adm-S)33Br16(Ag56Br).This work provides an example for the study of large-sized metal nanoclusters and nanocluster-based elec-trocatalysts.
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