Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Center of Advanced Nanocatalysis (CAN-USTC), CAS Centre for Excellence and Synergetic Innovation Centre in Quantum Information and Quantum Physics, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
Nano Lett. 2015 May 13;15(5):2875-80. doi: 10.1021/nl5045132. Epub 2015 Apr 7.
Bimetallic Au75Pd25 nanocrystals with shapes of icosahedron and octahedron were synthesized by adding different amounts of iodide ions, and were employed as catalysts for solvent-free aerobic oxidation of cyclohexane. Although both icosahedrons and octahedrons were bounded by {111} facets, the turnover frequency number of Au75Pd25 icosahedrons reached 15,106 h(-1), almost three times as high as that of Au75Pd25 octahedrons. The conversion of cyclohexane reached 28.1% after 48 h using Au75Pd25 icosahedrons, with the selectivity of 84.3% to cyclohexanone. Density functional theory calculations along with X-ray photoelectron spectroscopy examinations reveal that the excellent catalytic performance of AuPd icosahedrons could be ascribed to twin-induced strain and highly negative charge density of Au atoms on the surface.
具有二十面体和八面体形状的双金属 Au75Pd25 纳米晶体通过添加不同量的碘离子合成,并被用作无溶剂有氧氧化环己烷的催化剂。尽管二十面体和八面体都由 {111} 面构成,但 Au75Pd25 二十面体的周转频率数达到了 15106 h-1,几乎是 Au75Pd25 八面体的三倍。使用 Au75Pd25 二十面体 48 小时后,环己烷的转化率达到 28.1%,环己酮的选择性为 84.3%。密度泛函理论计算和 X 射线光电子能谱研究表明,AuPd 二十面体优异的催化性能可归因于孪晶诱导应变和表面 Au 原子的高度负电荷密度。