Reduced-Graphene-Oxide with Traces of Iridium or Gold as Active Support for Pt Catalyst at Low Loading during Oxygen Electroreduction

TL;DR

This study explores reduced-graphene-oxide-supported gold or iridium nanoparticles as active carriers for platinum catalysts, demonstrating enhanced oxygen electroreduction activity and reduced peroxide formation in acid media.

Contribution

It introduces a novel catalyst system using reduced graphene oxide with trace gold or iridium to improve platinum-based oxygen reduction catalysts.

Findings

High electrocatalytic activity of platinum on reduced graphene oxide-supported Au or Ir.

Reduced graphene oxide support decreases hydrogen peroxide formation.

Interactions between gold and the support may activate catalytic sites.

Abstract

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.