Rotating ring–disc electrode study of the enhanced oxygen evolution on an activated ruthenium electrode

Abstract

The relationship between stability and electrocatalytic efficiency for the oxygen evolution reaction and ruthenium dissolution in 0.5 mol dm^–3 H₂SO₄ was determined using a rotating ring–disc electrode. Two different types of ruthenium electrode were used: one with ruthenium freshly electrodeposited on platinum and the other electrochemically activated by square-wave pulses from –0.2 V to +0.85 V vs. SCE. Both exhibited different electrocatalytic properties and current efficiencies for ruthenium dissolution. It was shown that the enhanced electrocatalytic efficiency of the activated electrode was 86% electrocatalytic. Both types of electrode were stable during potentiodynamic oxide formation and oxide reduction; the significant dissolution of ruthenium took place only at high positive potentials accompanied by oxygen evolution.