Investigation of iridium composition in Ti1–xIrxO2 (x = 0.1, 0.2, 0.3) nanostructures as potential supports for platinum in methanol electro-oxidation

To overcome the disadvantages of commercial carbonaceous catalysts in direct methanol fuel cells (DMFCs), novel Pt/Ti 1– x Ir x O 2 catalysts are fabricated in this study. Simultaneously, the influence of the Ir composition in the support on the electrocatalytic activities and physicochemical properties of Pt/Ti 1– x Ir x O 2 catalysts is also evaluated. Ti 1– x Ir x O 2 materials with the tunable Ir composition ( x = 0.1, 0.2, 0.3) synthesized via a simple and green hydrothermal route exhibited much higher electrical conductivity and surface area than the undoped TiO 2 . Furthermore, the well-distributed Pt nanoparticles (NPs) with small sizes (∼3 nm) over supports were obtained by using a modified chemical reduction route. Electrochemical results revealed that a series of 20 wt. % Pt/Ti 1– x Ir x O 2 catalysts exhibited superior durability and electrochemical activity toward the methanol oxidation reaction to the commercial 20 wt. % Pt/C (E-TEK) catalyst. According to these results, Ti 1– x Ir x O 2 materials seem to be very promising as a stable catalyst support in the harsh medium of DMFCs.