Cathodic corrosion as a facile and universal method for scalable preparation of powdery single atom electrocatalysts

Top-down strategy has been widely applied for synthesis of metal single atom catalysts (SACs) via converting metal nanoparticles or bulk metals into atomically dispersed species. Here, we report a simple electrochemical atomic migration strategy for top-down synthesis of SACs via a facile cathodic corrosion process without involving high temperature or harsh atmosphere. Atoms of metal nanoparticles on cathode are firstly disbanded under high negative voltage, and emitted into the electrolyte in the form of atomic metal anions in Zintl phase. The escaped atomically dispersed metal species are then oxidized by water molecules and captured by the defects on the pre-added nitrogen doped carbon carriers in the electrolyte. This cathodic corrosion strategy is confirmed to be suitable for scalable synthesis of kinds of metal SACs (e.g., Pt, Pd, and Ir) on doped carbon materials. Typically, the as-prepared nitrogen doped carbon powder supported Pt SACs exhibit superior catalytic activity toward hydrogen evolution reaction (HER) with a low overpotential of 0.024 V at 10 mA·cm⁻² and a low Tafel slope of 29.7 mV·dec⁻¹ as well as a long-term durability.