Preparation and characterization TiOx-Pt/C catalyst for hydrogen oxidation reaction
Preparation and characterization TiOx-Pt/C catalyst for hydrogen oxidation reaction
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DOI：
10.1039/b822249e
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发表时间：
2009-01-01
影响因子：
3.3
通讯作者：
Krstajic, N. V.
中科院分区：
文献类型：
--
作者：
Elezovic, N. R.;Babic, B. M.;Krstajic, N. V.
用改进的乙二醇法在工业碳载体(Vulcan XC-72)上首次合成了铂/碳催化剂。然后采用多元醇法和TiOx后沉积法制备了TiOx-Pt/C催化剂。用X射线衍射仪、透射电子显微镜和能谱技术对合成的催化剂进行了表征。结果表明，铂碳催化剂纳米颗粒均匀分布在碳载体上，平均粒径约为2.4 nm。用TiOx催化剂掺杂的铂/碳的颗粒大小和分布非常相似，这证实了TiOx的后沉积并没有导致铂纳米颗粒的显著长大。用循环伏安法测定了催化剂的电化学活性表面积，用旋转圆盘电极上的线性扫描伏安法研究了氢氧化动力学。推导了用于分析的动力学方程，考虑了HOR动力学的可逆性或不可逆性。结果表明，所研究催化剂的氢氧化反应为电化学可逆反应。测定的动力学参数塔菲尔斜率为28 mV dec(-1)，交换电流密度约为0.4 mA cm(铂)(-2)，与通常报道的铂催化剂在酸性溶液中的氢氧化反应的结果一致。
The hydrogen oxidation reaction (HOR) was studied at the home made TiOx-Pt/C nanocatalysts in 0.5 mol dm(-3) HClO4 at 25 degrees C. Pt/C catalyst was first synthesized by modified ethylene glycol method (EG) on commercially used carbon support (Vulcan XC-72). Then TiOx-Pt/C catalyst was prepared by the polyole method followed by TiOx post-deposition. The synthesized catalyst was characterized by XRD, TEM and EDX techniques. It was found that Pt/C catalyst nanoparticles were homogenously distributed over carbon support with the mean particle size of about 2.4 nm. The quite similar, homogenous distribution and particle size were obtained for Pt/C doped by TiOx catalyst which was the confirmation that TiOx post-deposition did not lead to significant growth of the Pt nanoparticles. The electrochemically active surface area of the catalyst was determined by using the cyclic voltammetry technique.The kinetics of hydrogen oxidation was investigated by the linear sweep voltammetry technique at the rotating disc electrode (RDE). The kinetic equations used for the analysis were derived considering the reversible or irreversible nature of the kinetics of the HOR. It was found that the hydrogen oxidation reaction for an investigated catalyst proceeded as an electrochemically reversible reaction. The values determined for the kinetic parameters-Tafel slope of 28 mV dec(-1) and exchange current density about 0.4 mA cm(Pt)(-2) are in good agreement with usually reported values for a hydrogen oxidation reaction with platinum catalysts in acid solutions.