Dry‐Solid‐Electrochemical Synthesis: A General Method for Large Scale Synthesis of Single‐Atom Catalysts with High Metal loadings.

Single‐atom catalysts (SACs) with high metal loadings are highly desirable but still challenging for large scale synthesis. Here we report a new technique named as dry‐solid‐electrochemical synthesis (DSES) for a general large‐scale synthesis of SACs with high metal loadings in an energy‐conservation and environment‐friendly way. With it, a series of pure carbon‐supported metal SACs (Platinum up to 35.0 wt %, Iridium 21.2 wt %, Ruthenium 20.4 wt % and Iron 17.6 wt %) with high metal loadings were obtained. Particularly, a Pt SAC with Pt 23.9 wt % and remarkable oxygen reduction reaction (ORR) performance in fuel cells is synthesized on kilogram scale. Based on multiple control experiments, a unique redox mechanism for DSES process is proposed: metal precursors on conductive supports are reduced to metals via a homolytic cleavage of metal‐halogen bonds by the attacking of electrons flowing through the dry solid phase. Such versatile technique paves a new economical and environment‐friendly pathway for fabricating high‐metal‐loading SACs or atomic dispersion catalysts. [ABSTRACT FROM AUTHOR]