LOW ENERGY ELECTRON DIFFRACTION STUDIES OF GAS ADSORPTION ON PLATINUM (100) SINGLE CRYSTAL SURFACE

The chemisorption of various gases (H2, N2, N2O, O2, CO, CO2, CH4, C2H6, C2H2 and C2H4) on the Pt(100) single crystal surface has been studied, using low energy electron diffraction (LEED), mass spectrometry, flash desorption and work function measurements, at gas pressures usually ≤ 1 × 10-7 Torr and at temperatures between 25°C-1400°C. The Pt(100) substrate was characterized by a (5 × 1) surface structure. Those gases which chemisorbed on the platinum surface (CO, H2, C2H2 and C2H4) formed ordered surface structures. Also, a further surface structure was formed by the co-adsorption of H2 and CO. A strong affinity was found between carbon, or carbon-containing molecules, and the platinum surface. Carbon monoxide adsorbed in three bonding states on the (100) surface. The adsorption results differed somewhat from those observed in adsorption experiments performed at higher gas pressures. © 1968.