High conductivity of novel Ti0.9Ir0.1O2 support for Pt as a promising catalyst for low-temperature fuel cell applications

The novel nanostructured Ti 0.9 Ir 0.1 O 2 acting as a potential catalyst support for Pt in fuel cell applications was easily synthesized by means of a facile and simple low-temperature hydrothermal process without using any surfactants and further heat treatment. Interestingly, even in low iridium doping concentration, the Ti 0.9 Ir 0.1 O 2 support possessed the high electronic conductivity of 0.016 S/cm, which was ∼10 5 times as high as pure TiO 2 (4.15 × 10 −7  S/cm), suggesting the efficient doping of iridium into TiO 2 lattice. Furthermore, the modified chemical reduction route utilized to prepare the 20 wt % Pt/Ti 0.9 Ir 0.1 O 2 electrocatalyst exhibited the good anchoring and uniform distribution of Pt nanoparticles (NPs) (∼3 nm) over Ti 0.9 Ir 0.1 O 2 surface and thus eventually resulted in the high electrochemical surface area (∼85.08 m 2 /gPt) compared to that of the commercial 20 wt % Pt/C (E-TEK) catalyst (∼69.21 m 2 /gPt). The cyclic voltammetry results in the methanol media revealed that the 20 wt % Pt/Ti 0.9 Ir 0.1 O 2 displayed the superior electrocatalytic activity compared to the 20 wt % Pt/C (E-TEK) catalyst towards the methanol electro-oxidation. For instance, the 20 wt % Pt/Ti 0.9 Ir 0.1 O 2 catalyst possessed the higher oxidation current density (∼28.8 mA/cm 2 ), the lower onset potential (∼0.12 V) and the higher I f /I b ratio in comparison with the commercial 20 wt % Pt/C (E-TEK) catalysts. It is worth noting that the chronoamperometry results also indicated that the 20 wt % Pt/Ti 0.9 Ir 0.1 O 2 exhibited higher durability than the commercial 20 wt % Pt/C (E-TEK) catalyst. Beside introducing novel Ti 0.9 Ir 0.1 O 2 material, these results also offer a pathway of exploring the low dopants content of Ti x Ir 1-x O 2 material to serve as a good catalyst support for many fuel cell applications.