Novel nanorod Ti0·7Ir0·3O2 prepared by facile hydrothermal process: A promising non-carbon support for Pt in PEMFCs

Late transition metal doped TiO 2 has been exploited for generating efficient catalyst support by enhancing electrical conductivity and modifying properties of TiO 2 . The Ti 0·7 Ir 0·3 O 2 nanorod (NRs), a novel catalyst support for Pt nanoparticles , was prepared for the first time via single-step hydrothermal process at low temperature using IrCl 3 ·3H 2 O and TiCl 4 as starting materials. We found that the Ti 0·7 Ir 0·3 O 2 NRs with 70–80 nm in length and 25–30 nm in width is successful prepared at 210 °C for 12 h without utilizing surfactants or stabilizers . In addition, the Ti 0·7 Ir 0·3 O 2 NRs was presented principally as a single-phase solid with the TiO 2 is in the rutile form with high crystallinity without using further treatment after synthesis. More importantly, we found that the Ti 0·7 Ir 0·3 O 2 NRs possesses high electrical conductivity (0.028 S cm −1 ) dealing the intrinsically non-conducted drawback of TiO 2 . The Pt nanoparticles were then deposited on the support of Ti 0·7 Ir 0·3 O 2 NRs via chemical reduction method. The properties of 20 wt % Pt/Ti 0·7 Ir 0·3 O 2 NRs electrocatalyst were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), the cyclic voltammetry (CV). The uniformly distributed small Pt nanoparticles (3–4 nm diameter) were well adhered to the Ti 0·7 Ir 0·3 O 2 NRs. The electrochemically active surface area (ECSA) of 20 wt % Pt/Ti 0·7 Ir 0·3 O 2 NRs was higher than that of the commercial 20 wt % Pt/C (E-TEK) due to the small size and good dispersion of Pt nanoparticles on the surface of Ti 0·7 Ir 0·3 O 2 NRs. Moreover, the ECSA value of the Pt/Ti 0·7 Ir 0·3 O 2 NRs retained up to 88% after 2000 cycles of cyclic voltammetry, suggesting the high stability of catalyst resulted from strong metal support interaction (SMSI) of Titania-based materials with the noble metals. More importantly, the onset potential of Pt/Ti 0·7 Ir 0·3 O 2 NRs catalyst towards oxygen reduction reaction is more positive (∼80 mV) compared to commercial Pt/C, indicating the high catalytic activity of the Pt/Ti 0·7 Ir 0·3 O 2 NRs catalyst. The results of this research suggested that novel Ti 0·7 Ir 0·3 O 2 NRs could be applied as promising robust non-carbon support for Pt. This research also creates a preliminary step for investigating systematically promising Iridium doped Titania materials.