Thiolated, Reduced Palladium Nanoclusters with Resolved Structures for the Electrocatalytic Reduction of Oxygen

Although thiolated, reduced Group 11 metal nanoclusters with atomic monodispersity have been repeatedly reported in the past decade, their Pd analogues have not been reported thus far. In this work, we provide a resolution for the challenging synthesis and obtain for the first time an atomically monodisperse thiolated, reduced Pd (q=+0.75) nanocluster with a di-tetrahedron Pd₈ kernel and a +3 charged interstitial B atom, as revealed by ESI-MS, SCXRD, etc. μ-6 B is found for the first time in Group 10 and 11 metal nanoclusters. More importantly, the as-obtained Pd nanoclusters show better catalytic activity compared to 1.4 nm Pd nanoparticles, Pd₂ complexes and even a commercial Pt/C catalyst for the oxygen reduction reaction (ORR), having significant implications for the influence of the metal charge state and space structure on the catalytic activity.