Preparation of PtSn/C electrocatalysts with improved activity and durability toward oxygen reduction reaction by alcohol-reduction process
Preparation of PtSn/C electrocatalysts with improved activity and durability toward oxygen reduction reaction by alcohol-reduction process
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DOI：
10.1016/j.matchemphys.2012.04.065
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发表时间：
2012-08
影响因子：
4.6
通讯作者：
Bing-Jian Su;Kuan-Wen Wang;Tien-chun cheng;Chung‐Jen Tseng
中科院分区：
文献类型：
--
作者：
Bing-Jian Su;Kuan-Wen Wang;Tien-chun cheng;Chung‐Jen Tseng
采用醇还原法制备了PtSn/C电催化剂，用于氧还原反应。用能谱仪、X射线衍射仪和高分辨透射电镜对催化剂的物理和形貌进行了表征。采用循环伏安法、线性扫描伏安法和长期耐久性测试等方法对材料的电化学性能进行了分析。结果表明，由于PtSn/C催化剂中SnO 2相的形成，在pH 12条件下制备的样品比pH 9条件下制备的样品具有更小的粒径。当在回流过程之前添加碳载体时，具有4.8nm尺寸的合金纳米颗粒均匀地分散在C载体上。虽然PtSn 12的Pt负载量仅为商业Pt/C的75%左右，但由于催化剂活性的提高和O2在催化剂表面的吸附和解离，其ORR活性提高到131%。此外，基于加速耐久性测试，PtSn 12在500次循环后的ORR活性是Pt/C的1.34倍，这表明由于PtSn/C中SnO 2的共存，PtSn 12在酸性环境中的化学稳定性更高。
PtSn/C electrocatalysts were prepared by alcohol-reduction process for the oxygen reduction reaction. The physical and morphological properties of the synthesized catalysts were characterized by energy dispersive spectrometer, X-ray diffraction, and high resolution transmission electron microscope. The electrochemical performances were analyzed by cyclic voltammetry, linear scan voltammetry and long-term durability. Results show that samples prepared at pH 12 have smaller particle size than those prepared at pH 9 due to the formation of SnO2phases in PtSn/C catalysts. When the carbon support was added before the reflux process, the alloy nanoparticles having a size of 4.8 nm are uniformly dispersed on the C support. Although the Pt loading of PtSn12 is only about 75% of the commercial Pt/C, its ORR activity is promoted to 131% due to enhanced catalyst activity and O2adsorption and dissociation on the catalyst surface. Furthermore, based on the accelerated durability test, the ORR activity after 500 cycles of PtSn12 is 1.34 times higher than that of Pt/C, suggesting that PtSn12 is more chemically stable in the acid environment due to the coexistence of SnO2in PtSn/C.