摘要
Bimetallic PtxCuy nanocrystals （NCs） with well-defined hexa-pod morphology were synthesized via a wet chemistry approach. The as-synthesized convex NCs with dimensions of around 20 nm show exposed low-index （111） facets on the seeds and various high-index facets on the pods. The growth mechanism involved preferred growth along the 〈100〉 crystallographic direction on cuboctahedral seeds. The synthetic protocol could be applied to the synthesis of PtxCuy NCs with various Cu/Pt ratios. The electro-catalytic activity of the hexa-pod PtxCuy NCs supported on carbon black towards the oxygen reduction reaction （ORR） was studied. The hexa-pod PtCu2/C catalysts exhibit the highest specific activity （3.7 mA/cm^2pt） and mass activity （2.4 A/mget） reported to date for PtxCuy. Comparison with other morphological forms of PtxCuy indicated that the enhanced activity originated from morphological factors. The existence of high-index facets as well as abundant edges and steps on the pods could reasonably explain the enhanced catalytic activity. The hexa-pod PtxCuy/C catalysts also show high morphological stability and activity after accelerated durability tests. The as-synthesized hexa-pod PtxCuy NCs have high potential as cathode electro-catalysts for proton exchange membrane fuel cells.
二金属的磅 <sub> x </sub > 有明确的昆虫形态学的 Cu <sub> y </sub> nanocrystals (NC ) 经由一条湿化学途径被综合。有约 20 nm 表演的尺寸的同样综合的凸的 NC 暴露了低索引(111 ) 种子上的方面和豆荚上的各种各样的高索引的方面。生长机制沿着 cuboctahedral 上的结晶的方向播种的 <100> 包含了比较喜欢的生长。合成协议能被用于磅 <sub> x </sub 的合成 > 有各种各样的 Cu/Pt 比率的 Cu <sub> y </sub> NC。向氧减小反应(ORR ) 在碳黑色上支持的昆虫 PtxCuy NC 的电镀物品催化的活动被学习。昆虫 PtCu <sub>2</sub>/C 催化剂展出最高特定的活动(3.7 妈 / 厘米 <sub > 磅 </sub><sup>2</sup>) 和集体活动(2.4 A/mg <sub > 磅 </sub>) 报导了为磅 <sub> x </sub 标明日期 > Cu <sub> y </sub> 。有磅 <sub> x </sub 的另外的词法形式的比较 > Cu <sub> y </sub> 显示提高的活动从词法因素发源。豆荚上的高索引的方面以及丰富的边和步的存在能相当解释提高的催化活动。昆虫磅 <sub> x </sub > Cu <sub> y </sub>/C 催化剂也在加速的耐久性测试以后显示出高词法的稳定性和活动。同样综合的昆虫磅 <sub> x </sub > Cu <sub> y </sub> NC 为质子交换膜燃料房间作为阴极电镀物品催化剂有高潜力。
基金
We acknowledge the Microstructure Laboratory for Energy Materials （MLEM） at CUP for the technical support with TEM. We also acknowledge the funding support from the National Natural Science Foundation of China （No. 21303265）, Ph.D. Programs Foundation of Ministry of Education of China （No. 20130007120012） and Young Talent Award of CUP （No. YJRC-2013-46）.
