  Chemically-reduced graphene-oxide-supported gold or iridium nanoparticles are
considered here as active carriers for dispersed platinum with an ultimate goal
of producing improved catalysts for electroreduction of oxygen in acid medium.
Comparison is made to the analogous systems not utilizing reduced graphene
oxide. High electrocatalytic activity of platinum (loading up to 30 {\mu}g
cm-2) dispersed over the reduced-graphene oxide-supported Au (up to 30 {\mu}g
cm-2) or Ir (up to 1.5 {\mu}g cm-2) nanoparticles toward reduction of oxygen
has been demonstrated using cyclic and rotating ring-disk electrode (RRDE)
voltammetric experiments. Among important issues are possible activating
interactions between gold and the support, as well as presence of structural
defects existing on poorly organized graphitic structure of reduced graphene
oxide. The RRDE data are consistent with decreased formation of hydrogen
peroxide.
