Enhanced methanol electrooxidation activity of PtRu nanoparticles supported on H 2O 2-functionalized carbon black

Abstract

PtRu nanoparticles deposited on a carbon black sub-strate are catalysts commonly employed for the electro-oxidation of methanol and carbon monoxide-containinghydrogen feeds [1,2]. However, improvement of effectiveelectrocatalysts is an essential goal in the development ofa practical DMFC. The use of carbon black as a supportfor noble metals is frequent in the electrodes of polymermembrane electrolyte fuel cells, but the impact of thechemical and physical properties of the carbon on elect-rocatalytic performance are not yet sufficiently under-stood. The presence of oxygen surface groupsinfluences the surface behaviour of carbons to a consid-erable extent [3,4]. As examples, the wettability andadsorptive behaviour of a carbon, as well as its catalyticand electrical properties, are influenced by the natureand extent of such surface groups. The varying role ofoxygenated functionalities on the formation of the dis-persed platinum has been established [5–8], but not withan additional metal such as ruthenium. In the presentinvestigation we report how the performance in metha-nol electrooxidation of PtRu nanoparticles depositedon a carbon black substrate, previously functionalizedwith oxygen surface groups, is improved.A commercial Vulcan XC-72R (Cabot Co.) carbonblack was used as the support material. This carbonwas functionalized by treatment with an aqueousH