Sn-doped TiO_2 nanoparticles with high surface area of 125.7 m^2·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 Ti_(0.7)Sn_(0.3)O_2 support with an average size of 2.44 run.Electrochemical studies show that the Ti_(0.7)Sn_(0.3)O_2 nanoparticles have excellent electrochemical stability under a high potential compared to Vulcan XC-72.The as-synthesized Pt/Ti_(0.7)Sn_(0.3)O_2 exhibits high and stable electrocatalytic activity for the oxygen reduction reaction.The Pt/Ti_(0.7)Sn_(0.3)O_2 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/Ti_(0.7)Sn_(0.3)O_2is 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/Ti_(0.7)Sn_(0.3)O_2 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(C2H4N+3CH3SO-3, [Tri][MS]), an ionic conductor, was successfully synthesized. It exhibited high ionic conductivity of 18.60 m S cm-1at 140CdSC and reached up to 36.51 m S cm-1at 190CdSC. [Tri][MS] was first applied to modify Nafion membrane to fabricate [Tri][MS]/Nafion membrane by impregnation method at 150CdSC. The prepared composite membrane showed high thermal stability with decomposed temperature above 200CdSC in air atmosphere. In addition, the membrane indicated good ionic conductivity with 3.67 m S cm-1at 140CdSC and reached up to 13.23 m S cm-1at 180CdSC. 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 m W cm-2at 140CdSC and 4.90 m W cm-2at 150CdSC, which was much higher than that of Nafion membrane.
Jinkai HaoXiaojin LiShuchun YuYongyi JiangJiangshui LuoZhigang ShaoBaolian Yi
