Adsorbed states of oxygen on Pd(1 1 0) — Vibrational electron energy loss spectroscopy and low-energy electron diffraction studies

The adsorbed states of hydrogen on Pd(1 1 0) surfaces at 100–300 K have been studied using high-resolution electron energy loss spectroscopy (EELS) and low-energy electron diffraction (LEED). The observed losses are at 96, 118 and ∼ 165 meV for the (2 × 1)-H surface; 96 and ∼ 125 (shoulder) meV for the (1 × 2)-H surface formed at 100 K; ∼ 90 and 118 meV for the streaky (1 × 2)-H surface formed at 300 K. Tentative assignments of the losses are made. The adsorbed states of hydrogen are discussed correlating the EELS-LEED results with the thermal desorption and molecular beam diffraction studies which have previously been reported.