Hydrogen Peroxide Production in the Oxygen Reduction Reaction at Different Electrocatalysts as Quantified by Scanning Electrochemical Microscopy

摘要

We present data for H_(2)O_(2) production at eight different materials tested as electrocatalysts for the oxygen reduction reaction (ORR) in 0.5 M H_(2)SO_(4) (Hg, Au, Ag, Cu, Pt, Pd, Pd_(80)Co_(20), and Au_(60)Cu_(40)) using scanning electrochemical microscopy (SECM) as an alternative to the widely used rotating ring-disk electrode (RRDE) method. The amount of H_(2)O_(2) is related to the total number of electrons, n, found in the O_(2) reduction reaction, with n velence 2 showing only H_(2)O_(2) production and n velence 4 showing no H_(2)O_(2) formation. From the SECM study Hg shows n close to 2, whereas Pt and Pd_(80)Co_(20) show n-values near 4. The other materials show intermediate n-values as a function of potential.