Authors: T. Yamamoto, S. Ohnishi and N. Watari
Affilation: NEC Fundamental Resreach Labs., Japan
Pages: 482 - 485
Keywords: proton, Pt, DFT, water
We present theoretical studies of atomic and electronic structures calculations of hydrogen at Pt surfaces with H2O molecules by focusing on the mechanism of proton polarization in the fuel cells system by the density functional theory with the generalized gradient correction. We found two equilibrium hydrogen sites between a Pt surface and a H2O molecule in both Pt13 cluster and periodic surface systems: the chemisorption site on the Pt surface of 0.2 a.u. and hydronium-ion like site of 1.8 a.u. from the Pt(100) topmost layer in the case of the H2O/H/Pt(001)-c(6_6) surface. Based on the Mulliken charge analysis, we found hydrogen does not loose electron at the chemisorption site but ionizes at the hydronium ion site.