Spontaneous amorphous oxide-interfaced ultrafine noble metal nanoclusters for unexpected anodic electrocatalysis

Noble metals are considered a key branch of electrocatalysts. Unfortunately, their contributions to anodic reactions still face a big challenge. Here, guided by density functional theory, significant breakthroughs have been achieved by constructing a unique spontaneously oxidized interface in noble metal sub-nanocluster (SNC) catalysts depending on strong surface affinity. The spontaneous oxide interfaces with the amorphous covering on the rhodium (Rh) SNCs (diameter <2 nm). Turnover frequency of the Rh/RhOx catalyst reached 2.19 s−1 for the oxygen evolution reaction (OER) in alkaline media, 72.0-times and 3.3-times higher than those of Rh and Rh2O3, respectively. Moreover, the high activity can be maintained for at least 20 h at 50 mA cm−2. Such a unique strategy provides a general platform to largely facilitate the OER performances of platinum, palladium, and iridium catalysts, opening up a new and promising avenue for the design of noble metal catalysts for expansive applications.