Surface investigation of intermetallic PdGa(1̄ 1̄ 1̄)

Rosenthal, Dirk; Widmer, Roland; Wagner, R.; Gille, Peter; Armbrüster, Marc; Grin, Yuri; Schlögl, Robert und Gröning, Oliver (2012): Surface investigation of intermetallic PdGa(1̄ 1̄ 1̄). In: Langmuir, Bd. 28, Nr. 17: S. 6848-6856

Abstract

The intermetallic PdGa is a highly selective and potent catalyst in the semihydrogenation of acetylene, which is attributed to the surface stability and isolated Pd atom ensembles. In this context PdGa single crystals of form B with (1̄ 1̄ 1̄) orientation were investigated by means of X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), scanning tunneling microscopy (STM), X-ray photoelectron diffraction (XPD), and low-energy electron diffraction (LEED) to study the electronic and geometric properties of this surface. UPS and thermal desorption spectroscopy (TDS) were used to probe the chemisorption behavior of CO. The PdGa(1̄ 1̄ 1̄) surface exhibits a (1 × 1) LEED and a pronounced XPD pattern indicating an unreconstructed bulk-truncated surface. Low-temperature STM reveals a smooth surface with a (1 × 1) unit cell. No segregation occurs, and no impurities are detected by XPS. The electronic structure and the CO adsorption properties reveal PdGa(1̄ 1̄ 1̄) to be a bulk-truncated intermetallic compound with Pd-Ga partial covalent bonding.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften > Kristallographie und Materialwissenschaft
• Themengebiete: 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• Sprache: Englisch