OXYGEN-CHEMISORPTION ON PLATINUM SINGLE-CRYSTAL FACES IN SULFATE-SOLUTIONS

The potentiodynamic pulse technique was used to investigate oxygen chemisorption on an untextured polycrystalline Pt electrode and on the Pt single-crystal faces (111), (100), (110), and (311) in 3.3 M (NH4)2SO4 + 0.1 M H2SO4 solution at oxidation potentials between 1.0 and 3.5 V (rhe). Cathodic potentiodynamic curves for oxygen reduction were analyzed; the peaks in these curves were assigned to three forms of chemisorbed oxygen, viz., ChO-1, ChO-2, and ChO-3. The chemisorption properties of Pt surfaces with different structure types were.found to be highly anisotropic. Their electrocatalytic behavior in ammonium peroxydisulfate electrosynthesis and their chemisorption behavior were.found to be correlated.