The Simple Synthesis of High Metal Loading Single-Atom Catalysts via Chelate Fixation

Supported atomically dispersed metal catalysts are at the frontier of catalysis research, promising combined advantages of well-defined sites and high selectivity, with high stability and easy separation characterizing solid catalysts. We report that addition of an organic chelating agent in the final stage of impregnation, allows the metal precursor to be anchored and isolated without the need for anchoring sites on the support. The resulting isolated atoms are characterized with scanning transmission electron microscopy, X-ray photoelectron spectroscopy, and thermal desorption of carbon monoxide. This “chelate fixation” (CheFi) method can yield relatively high loadings of single atoms (e.g., Pt, Ru, Ir), up to at least 1 atom nm-2 on a variety of carbon (e.g., black, activated carbon, diamond) and oxide (e.g., TiO2, SiO2) supports.