Uniform size and composition tuning of PtNi octahedra for systematic studies of oxygen reduction reactions
Uniform size and composition tuning of PtNi octahedra for systematic studies of oxygen reduction reactions
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DOI：
10.1016/j.jcat.2013.09.008
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发表时间：
2014
影响因子：
7.3
通讯作者：
Shang-Wei Chou;Ying-Ren Lai;Ya Yun Yang;Chih‐Yuan Tang;M. Hayashi;Hsieh-Chih Chen;Hui-Lung Chen;P. Chou
中科院分区：
文献类型：
--
作者：
Shang-Wei Chou;Ying-Ren Lai;Ya Yun Yang;Chih‐Yuan Tang;M. Hayashi;Hsieh-Chih Chen;Hui-Lung Chen;P. Chou
通过控制特定的晶面-表面活性剂结合，实现了由8个{1+1+1}面包围的PtNi八面体的均匀尺寸和成分调节。在这种化学方法中，最佳的二辛胺与油酸的比例是形成不同合金组成的PtNi八面体的关键因素，其组成分别为：Pt：NiO=18：6、12：12和10：14。仔细的电化学测试表明，所有PtNi八面体的氧还原反应(ORR)质量活性和比表面活性均优于商品铂/碳催化剂。火山形状的ORR增强趋势证明了Pt12Ni12八面体具有优越的ORR活性。结果表明，H、O、O2和OH物种在Pt12Ni12(1：1：1)表面的吸附能远高于Pt18Ni6(1：1：1)和Pt10Ni14(1：1：1)表面，而分子吸附的H2O产物在Pt12Ni12(1：1：1)表面的吸附能最低。
Uniform size and composition tuning of PtNi octahedra enclosed by 8 {1 1 1} facets were achieved by the control of specific crystal facet–surfactant bindings. In this chemical method, the optimal ratio of dioctyl amine to oleic acid is a key factor in the formation of PtNi octahedra with different alloying compositions, Pt:Ni = 18:6, 12:12, and 10:14. Careful electrochemical examinations show that the oxygen reduction reaction (ORR) mass activity and specific area activity of all PtNi octahedra outperform those of commercial Pt/C catalyst. The volcano-shaped trend of ORR enhancement proves that Pt12Ni12octahedra have superior ORR activities. Further firm support is provided by the theoretical approach, which concludes that the adsorption energies of the H, O, O2, and OH species on a surface of Pt12Ni12(1 1 1) are much higher than those for Pt18Ni6(1 1 1) and Pt10Ni14(1 1 1) counterparts, whereas the molecularly adsorbed H2O product is calculated to be the lowest in adsorption energy on the Pt12Ni12(1 1 1) surface.