Comparison of the Catalytic Properties of 25-Atom Gold Nanospheres and Nanorods

The catalytic properties of two nanocluster catalysts with atomically precisely known structures, icosahedral two-shelled Au25(SC2H4Ph)18 nanospheres and biicosahedral Au25(PPh3)10(SC2H4Ph)5Cl2 nanorods, were compared. Their catalytic performance in the two reactions of the selective oxidation of styrene and chemoselective hydrogenation of α,β-unsaturated benzalacetone was investigated. The catalytic activities of icosahedral Au25(SC2H4Ph)18 nanospheres were superior to those of the bi-icosahedral Au25(PPh3)10(SC2H4Ph)5Cl2 nanorods for both reactions. The better catalytic performance of the Au25(SC2H4Ph)18 nanospheres can be attributed to their unique core-shell (Au13/Au12) geometric structure that has an open exterior atomic shell and to their electronic structure with an electron-rich Au13 core and an electron-deficient Au12 shell.