Effect of Specific Heavy Doping of Silver Atoms into the Icosahedral Au13 on Electronic Structure and Catalytic Performance

The exploration of specific heavy doping of silver atoms into icosahedral Au13 clusters and their electronic structures and properties has been somewhat limited. Herein, we report two heavily Ag doped nanoclusters, [Au7Ag6(C7H4NOS)4(Dppf)3Cl]0 and [Au7Ag6(C7H4NOS)3(Dppf)3Cl](SbF6) (Au7Ag6-0 and Au7Ag6-1, respectively) [C7H4NOSH = 2-mercaptobenzoxazole, and Dppf = 1,1′-bis(diphenylphosphino)ferrocene]. The electronic structures and superatomic orbitals of nanoclusters were determined by density functional theory (DFT) calculations, and the energy degeneracy of the superatomic orbitals of Au7Ag6-1 is higher than that of Au7Ag6-0. Transient absorption spectroscopy was performed, revealing that Au7Ag6-0 significantly extends the excited-state lifetime. Both nanoclusters were supported on activated carbon for the oxygen reduction reaction. DFT calculations confirm that the catalytic activities mainly stem from the carbon atom of ferrocene rather than the iron atom. This study not only sheds light on the preparation of icosahedral alloy clusters but also provides insights into the regulation of icosahedral superatomic structure and electrocatalytic properties.

将银原子高浓度掺杂至二十面体Au₁₃团簇并探究其电子结构与相关性质的研究仍较为有限。本文报道了两种高银掺杂量的纳米团簇：[Au₇Ag₆(C₇H₄NOS)₄(Dppf)₃Cl]⁰与[Au₇Ag₆(C₇H₄NOS)₃(Dppf)₃Cl](SbF₆)（分别记为Au7Ag6-0与Au7Ag6-1），其中C₇H₄NOSH为2-巯基苯并恶唑（2-mercaptobenzoxazole），Dppf为1,1'-双(二苯基膦基)二茂铁（1,1′-bis(diphenylphosphino)ferrocene）。本研究通过密度泛函理论（density functional theory, DFT）计算解析了纳米团簇的电子结构与超原子轨道，发现Au7Ag6-1的超原子轨道能级简并度高于Au7Ag6-0。采用瞬态吸收光谱表征后发现，Au7Ag6-0的激发态寿命显著延长。将两种团簇均负载于活性炭上用于氧还原反应测试，DFT计算证实其催化活性主要来源于二茂铁的碳原子而非铁原子。本研究不仅为二十面体合金团簇的制备提供了参考，也为调控二十面体超原子结构与电催化性能提供了新的见解。