Electroanalysis of Ethanol Oxidation and Reactivity of Platinum-Ruthenium Catalysts Supported onto Nanostructured Titanium Dioxide Matrices

Abstract

This study concentrates on the development of catalytic materials capable of enhancing oxidation of ethanol particularly at low potentials, i.e. at conditions resembling operation of anodes in low temperature fuel cells. Indeed, the ethanol oxidation currents measured under voltammetric and chronoamperometric conditions have been significantly increased following dispersing bimetallic PtRu nanoparticle (~4 nm) catalysts over TiO 2 (80% anatase, 20% rutile) nanostructures (~20-30 nm) supported onto multi-walled carbon nanotubes. The improvement in activity is attributed not only to better dispersion of PtRu centers (some increase of active surface area) or improved (carbon-nanotube-assisted) propagation of electrons at the catalytic interface but also to the presence of hydroxyl groups and high mobility of protons at neighboring (to PtRu) TiO 2 . Further, specific interactions between TiO 2 and Pt or Ru metallic components are feasible. Importance of addition of TiO 2 is also evident from kinetic analysis based on measurements of steady-state currents at different concentrations. . The Author(s) 2015.