On Dissolved Oxygen in Bulk Platinum

Abstract

The hydrogen overvoltage was determined on the front side of a bright Pt foil in 2N H2SO4 solution while the solution on the back side was stirred with H2, N2, or 02. No change in the ~ was detected when the foil was connected as a diaphragm and when H2 stirring was replaced with 02 stirring on the back side. With the foil connected as a bielectrode, the ~ increased after an induction period depending on the thickness of the .foil when H2 stirring was" replaced with 02 stirring on the back side. These results indicate that under anodic polarization, oxygen can be dissolved in Pt. The dissolved oxygen can penetrate to the front side of the Pt foil where its presence as dermasorbed oxygen modified the catalytic activity of the Pt surface for the H2 evolution reaction. In the absence of anodization, oxygen sorbed from solution can penetrate the Pt lattice no further than the dermasorbed region.