Simple and Scalable Mechanochemical Synthesis of Noble Metal Catalysts with Single Atoms toward Highly Efficient Hydrogen Evolution

Designing a facile strategy to access active and atomically dispersed metallic catalysts are highly challenging for single atom catalysts (SACs). Herein, a simple and fast approach is demonstrated to construct Pt catalysts with single atoms in large quantity via ball milling Pt precursor and N-doped carbon support (K₂PtCl₄@NC-M; M denotes ball-milling). The as-prepared K₂PtCl₄@NC-M only requires a low overpotential of 11 mV and exhibits 17-fold enhanced mass activity for the electrochemical hydrogen evolution compared to commercial 20 wt% Pt/C. The superior hydrogen evolution reaction (HER) catalytic activity of K₂PtCl₄@NC-M can be attributed to the generation of Pt single atoms, which improves the utilization efficiency of Pt atoms and the introduction of Pt-N₂C₂ active sites with near-zero hydrogen adsorption energy. This viable ball milling method is found to be universally applicable to the fabrication of other single metal atoms, for example, rhodium and ruthenium (such as Mt-N₂C₂, where Mt denotes single metal atom). This strategy also provides a promising and practical avenue toward large-scale energy storage and conversion application.