Nanostructured PtRu/C as anode catalysts prepared in a pseudomicroemulsion with ionic surfactant for direct methanol fuel cell.
Nanostructured PtRu/C as anode catalysts prepared in a pseudomicroemulsion with ionic surfactant for direct methanol fuel cell.
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DOI：
10.1021/jp051443y
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发表时间：
2005-07
期刊：
影响因子：
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通讯作者：
Weilin Xu;T. Lu;Changpeng Liu;W. Xing
中科院分区：
文献类型：
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作者：
Weilin Xu;T. Lu;Changpeng Liu;W. Xing
以H(2)PtCl(6)、RuCl(3)和碳粉的混合浓溶液为水相，环己烷油相，十二烷基苯磺酸钠(C(18)H(29)NaO(3)S)离子表面活性剂和助表面活性剂正丁醇(C(4)H(10)O)为油包水假微乳液，制备了纳米结构PtRu/C催化剂。合成了两种不同成分的PtRu/C纳米催化剂（催化剂1，Pt 20 wt%，Ru 15 wt%；催化剂2，Pt 20 wt%，Ru 10 wt%）。通过透射电子显微镜、X射线衍射、X射线光电子能谱和热重分析对催化剂进行了表征，发现颗粒为纳米尺寸（2-4 nm），继承了Pt面心立方结构，其中Pt和Ru主要处于零价氧化态。在这些催化剂中还发现了氧化钌和水合氧化钌（RuO(x)()H(y)()）。这些催化剂上甲醇氧化的循环伏安图（CV）和计时电流分析表明，与低Ru含量（10 wt%）的催化剂2相比，较高Ru含量（15 wt%）的催化剂1对甲醇氧化具有更高且更持久的电催化活性。催化剂 1 和 2 的 CV 结果有力地支持了 PtRu/C 催化剂用于甲醇氧化的双功能机制。使用这两种 PtRu/C 作为阳极催化剂的直接甲醇单电池的数据表明，在 80 ℃ 下，使用催化剂 1 的电池比使用催化剂 2（OCV = 0.70 V，P(max) = 56 mW/cm(2)）的电池具有更高的开路电压（OCV = 0.75 V）和最大功率密度（78 mW/cm(2)）。
Nanostructured PtRu/C catalysts have been prepared from a water-in-oil pseudomicroemulsion with the aqueous phase of a mixed concentrated solution of H(2)PtCl(6), RuCl(3), and carbon powder, oil phase of cyclohexane, ionic surfactant of sodium dodecylbenzene sulfonate (C(18)H(29)NaO(3)S), and cosurfactant n-butanol (C(4)H(10)O). Two different composing PtRu/C nanocatalysts (catalyst 1, Pt 20 wt %, Ru 15 wt %; catalyst 2, Pt 20 wt %, Ru 10 wt %) were synthesized. The catalysts were characterized by transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, and thermogravimetric analysis, and the particles were found to be nanosized (2-4 nm) and inherit the Pt face-centered cubic structure with Pt and Ru mainly in the zero valance oxidation state. The ruthenium oxide and hydrous ruthenium oxide (RuO(x)()H(y)()) were also found in these catalysts. The cyclic voltammograms (CVs) and chronoamperometries for methanol oxidation on these catalysts showed that catalyst 1 with a higher Ru content (15 wt %) has a higher and more durable electrocatalytic activity to methanol oxidation than catalyst 2 with low Ru content (10 wt %). The CV results for catalysts 1 and 2 strongly support the bifunctional mechanism of PtRu/C catalysts for methanol oxidation. The data from direct methanol single cells using these two PtRu/C as anode catalysts show the cell with catalyst 1 has higher open circuit voltage (OCV = 0.75 V) and maximal power density (78 mW/cm(2)) than that with catalyst 2 (OCV = 0.70 V, P(max) = 56 mW/cm(2)) at 80 degrees C.