Protons Crossing Triple Phase Boundaries based on Pd and Barium Zirconate: A Density Functional Theory Study

摘要

Density functional theory calculations are used to address the energetics of protons crossing "triple phase boundaries" based on Pd and barium zirconate. Our calculations show that the proton transfer reaction at these triple phase boundaries is controlled by the terminal layer of the electrolyte in contact with the metallic catalyst and gas phase. Hydrogen spilling onto the electrolyte surface is energetically favored at peripherical sites of the metal-electrolyte interface, and proton incorporation into the sub-surface region of the electrolyte involves energies of the order of 1 eV. At the triple phase boundary, the energy cost associated with the proton transfer reaction is controlled by both the nature of chemical contact and the Schottky barrier at the metal-electrolyte interface.