A new synthesis of a highly dispersed and CO tolerant PtSn/C electrocatalyst for low-temperature fuel cell; its electrocatalytic activity and long-term durability
A new synthesis of a highly dispersed and CO tolerant PtSn/C electrocatalyst for low-temperature fuel cell; its electrocatalytic activity and long-term durability
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DOI：
10.1016/j.apcatb.2009.01.011
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发表时间：
2009-07
影响因子：
22.1
通讯作者：
Dong-Ha Lim;D. Choi;Weon-Doo Lee;Ho-In Lee
中科院分区：
文献类型：
--
作者：
Dong-Ha Lim;D. Choi;Weon-Doo Lee;Ho-In Lee
开发了一种通过硼氢化物还原和水热处理合成高分散纳米级PtSn/C电催化剂的有效方法。从XRD谱图上看，随着Sn含量的增加，PtSn/C催化剂的Pt（220）峰与Pt/C催化剂相比，在2θ值下有轻微的位移，表明合金的形成。通过红外透射电镜（HR-TEM）分析，PtSn纳米颗粒在碳表面的平均粒径约为2.3nm，与XRD数据一致。XPS结果表明，金属体Pt(0)向更高结合能的轻微转变是由于金属-载体相互作用和纳米尺寸效应的显著贡献。与商业Pt/C催化剂相比，PtSn/C催化剂上的甲醇和CO氧化发生在更低的电位下。这一结果表明，锡具有促进吸附CO在较低电位下氧化的能力。在单电池和加速耐久性试验中，由于PtSn合金和Sn氧化物共存，3Pt1Sn/C催化剂在纯h2气体和含co的h2气体下表现出更高的性能，在0.5M h2so4溶液下表现出比商用Pt/C催化剂更好的耐久性。
An effective method is developed for preparing highly dispersed and nano-sized PtSn/C electrocatalysts synthesized by borohydride reduction and subsequent hydrothermal treatment. From the XRD patterns, the Pt(220) peak of the PtSn/C catalysts shift slightly to lower 2θ values with increasing Sn content, compared with that of the Pt/C catalyst, suggesting the alloy formation. Based on the HR-TEM, the PtSn nanoparticles show average particle sizes of approximately 2.3nm on the carbon surface, which is consistent with XRD data. The XPS result shows that the slight shift in the bulk metallic Pt(0) to higher binding energies is attributed to a significant contribution from the metal-support interaction and the nano-size effect. The methanol and CO oxidations on the PtSn/C catalysts occur at lower potentials as compared to the commercial Pt/C catalyst. This result suggests that Sn has the ability to promote the oxidation of adsorbed CO at lower potentials. In the single-cell and accelerated durability tests, the 3Pt1Sn/C catalyst shows higher performance under a pure H2and CO-containing H2gases and better durability under a 0.5M H2SO4solution than the commercial Pt/C catalyst, due to the coexistence of PtSn alloys and Sn oxides.