Imaging Gold Atoms in Site-Isolated MgO-Supported Mononuclear Gold Complexes

Metal oxide- and zeolite-supported mononuclear gold complexes have been inferred, on the basis of spectroscopic data, to be catalytically active for alkene hydrogenation and CO oxidation. However, direct evidence that the catalysts are isolated, individual gold complexes in the absence of gold clusters or particles has been missing. Now we report the first evidence of uniquely site-isolated gold complexes on high-area MgO-in the absence of gold clusters or particles; the images were obtained with aberration-corrected scanning transmission electron microscopy.