Preparation and characterization of Ti0.7Sn0.3O2 as catalyst support for oxygen reduction reaction

Sn-doped TiO2 nanoparticles with high surface area of 125.7 m(2).g(-1) are synthesized via a simple one-step hydrothermal method and explored as the cathode catalyst support for proton exchange membrane fuel cells. The synthesized support materials are studied by X-ray diffraction analysis, energy dispersive X-ray spectroscopy and transmission electron microscopy. It is found that the conductivity has been greatly improved by the addition of 30 mol% Sn and Pt nanoparticles are well dispersed on Ti0.7Sn0.3O2 support with an average size of 2.44 nm. Electrochemical studies show that the Ti0.7Sn0.3O2 nanoparticles have excellent electrochemical stability under a high potential compared to Vulcan XC-72. The as-synthesized Pt/Ti0.7Sn0.3O2 exhibits high and stable electrocatalytic activity for the oxygen reduction reaction. The Pt/Ti0.7Sn0.3O2 catalyst reserves most of its electrochemically active surface area (ECA), and its half wave potential difference is 11 mV, which is lower than that of Pt/XC-72 (36 mV) under 10 h potential hold at 1.4 V vs. NHE. In addition, the ECA degradation of Pt/Ti0.7Sn0.3O2 is 1.9 times lower than commercial Pt/XC-72 under 500 potential cycles between 0.6 V and 1.2 V vs. NHE. Therefore, the as synthesized Pt/TiO3Sn0.3O2 can be considered as a promising alternative cathode catalyst for proton exchange membrane fuel cells.