Sn-doped TiO2 nanoparticles with high surface area of 125.7 m2·g-1 are synthesized via a simple one-step hydrothermai 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 run.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/Ti0.7Sn0.3O2is 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/Ti0.7Sn0.3O2 can be considered as a promising alternative cathode,catalyst for proton exchange membrane fuel cells.
Yuan GaoMing HouZhigang ShaoChangkun ZhangXiaoping QinBaolian Yi
In this paper, 1,2,4-triazolium methanesulfonate （C_2H_4N_3^＋-CH_3SO_3^-, [Tri][MS]）, an ionic conductor, was successfully synthesized. It exhibited high ionic conductivity of 18.60 mS·cm^-1 at 140 ℃ and reached up to 36.51 mS·cm^-1 at 190 ℃. [Tri][MS] was first applied to modify Nation membrane to fabricate [Tri][MS]/Nafion membrane by impregnation method at 150 ℃. The prepared composite membrane showed high thermal stability with decomposed temperature above 200 ℃ in air atmosphere. In addition, the membrane indicated good ionic conductivity with 3.67 mS·cm^-1 at 140 ℃ and reached up to 13.23 mS·cm^-1 at 180 ℃. The structure of the [Tri][MS] and the composite membrane were characterized by FTIR and the compatibility of [Tri][MS] and Pt/C catalyst was studied by a cyclic voltammetry （CV） method. Besides, the [Tri][MS]/Nafion membrane （thickness of 65 μm） was evaluated with single fuel cell at high temperature and without humidification. The highest power density of [Tri][MS]/Nafion membrane was 3.20 mW·cm^-2 at 140 ℃ and 4.90 mW·cm^-2 at 150 ℃, which was much higher than that of Nation membrane.
Jinkai HaoXiaojin LiShuchun YuYongyi JiangJiangshui LuoZhigang ShaoBaolian Yi
