3D Noble‐Metal Nanostructures Approaching Atomic Efficiency and Atomic Density Limits

Abstract Noble metals have been widely used in catalysis, however, the scarcity and high cost of noble metal motivate researchers to balance the atomic efficiency and atomic density, which is formidably challenging. This article proposes a robust strategy for fabricating 3D amorphous noble metal‐based oxides with simultaneous enhancement on atomic efficiency and density with the assistance of atomic channels, where the atomic utilization increases from 18.2% to 59.4%. The unique properties of amorphous bimetallic oxides and formation of atomic channels have been evidenced by detailed experimental characterizations and theoretical simulations. Moreover, the universality of the current strategy is validated by other binary oxides. When Cu 2 IrO x with atomic channels (Cu 2 IrO x ‐AE) is used as catalyst for oxygen evolution reaction (OER), the mass activity and turnover frequency value of Cu 2 IrO x ‐AE are 1–2 orders of magnitude higher than CuO/IrO 2 and Cu 2 IrO x without atomic channels, largely outperforming the reported OER catalysts. Theoretical calculations reveal that the formation of atomic channels leads to various Ir sites, on which the proton of adsorbed * OH can transfer to adjacent O atoms of [IrO 6 ]. This work may attract immediate interest of researchers in material science, chemistry, catalysis, and beyond.