Effect of platinum present in multi-element nanoparticles on methanol oxidation

Abstract

Nanoparticles of Pt(x)Fe((100-x)/5)Co((100-x)/5)Ni((100-x)/5)Cu((100-x)/5)Ag((100-x)/5) (x = 22, 29, 52, 56) were prepared by the sputter depositions on pretreated carbon clothes with their electrocatalytic abilities for the methanol oxidation investigated. XRD analysis of the deposited nanoparticles indicated crystalline fcc phases and SEM images revealed apparent growths of nanoparticulate nodules. Their average sizes were found to increase with the deposition time. Cyclic voltammetry of the deposited samples demonstrated enhancements in the current responses with increasing Pt amount and deposition time. In mass activity, the Pt(52)Fe(11)Co(10)Ni(11)Cu(10)Ag(8) exhibited the highest values of 462-504 mA/mg. Identical process was conducted to fabricate electrodes with sputtered Pt and Pt(43)Ru(57). In comparison, the Pt(52)Fe(11) Co(10)Ni(11)Cu(10)Ag(8) showed moderate improvements over that of Pt but was still outperformed by the Pt(43)Ru(57). (C) 2008 Elsevier B.V. All rights reserved.