Interaction of hydrogen peroxide with a Pt(111) electrode

Resumo

Hydrogen peroxide is recognized as one of the most probable intermediate species during oxygen reduction reaction (ORR) on various metals. In this work, H 2 O 2 reduction and oxidation on Pt(111) have been studied in a non-adsorbing electrolyte by cyclic voltammetry and online electrochemical mass spectrometry. H 2 O 2 is oxidized and reduced into two different, but interrelated electron transfer processes. As the potential increases, the reduction of H 2 O 2 switches rapidly to its oxidation at ~ E > 0.9 V. The whole process exhibits a marked hysteresis in the mixed charge transfer-diffusion controlled potential region, together with current overshoots at E > 0.85 V and E < 0.27 V in quiescent solutions. At high potentials, Pt(111) oxides and O 2 evolution explain the current-potential characteristics, while at low potentials, hydrogen adsorption is at the origin of the current response. © 2012 Elsevier B.V.

Palavras-chave