Surface X-ray Scattering of Pd(110) and Pd(311) in Electrochemical Environments

Abstract

Real surface structures of Pd(110) = 2(111)-(111) and Pd(311) = 2(100)-(111) have been determined using surface X-ray scattering (SXS) at 0.5 V (RHE) in 0.1 M HClO₄ saturated with Ar and O₂. Both surfaces have unreconstructed (1 × 1) structures. These results differ from those of Pt(110) and Pt(311) of which surfaces are reconstructed to (1 × 2) in 0.1 M HClO₄. Interlayer spacing between the first and the second layer d₁₂ is expanded on Pd(110) in O₂ saturated solution, whereas the spacing d₁₂ on Pd(311) is larger than that of the bulk in both Ar and O₂ saturated solutions.