Abstract
Sn-doped TiO(2)-carbon composites were identified as promising multifunctional supports for Pt electrocatalysts, in which the oxide component enhances resistance against corrosion and strong metal-support interactions at the Pt-oxide boundary ensure high stability for the Pt nanoparticles. This work is devoted to the study of the influence of preliminary functionalization of the carbon on the properties of Pt/Ti(0.9)Sn(0.1)O(2)-C catalysts. The structural, compositional and morphological differences between the samples prepared using functionalized or unmodified carbon, as well as the effect of carbon pre-modification on the electrocatalytic behavior of the synthesized Pt catalysts, were investigated using TEM, XRD, XPS, nitrogen adsorption and electrochemical measurements. The presence of oxygen-containing functional groups on carbon treated with HNO(3) and glucose leads to the formation of a homogeneous coating of the carbon with dispersed crystallites of mixed oxide. Elemental mapping revealed the proximity of Sn species with highly dispersed (2-3 nm) Pt particles. Notably, the electrochemical results indicated enhanced activity in CO electrooxidation for both functionalized and unmodified carbon-containing catalysts. An improvement in the 10,000-cycle long-term stability of the catalyst prepared using functionalized carbon was evident compared to the catalyst with untreated carbon or reference Pt/C.