单个金属原子掺杂贵金属小团簇结构与物性的理论研究

Small bimetallic clusters exhibit many peculiar physical and chemical properties and have attracted much attention due to the prominent quantum size effect, surface effect, and synergistic effect between different elements.The current experimental techniques, however, are still not sufficient for the accurate characterization on the structure and dimension size of small clusters. Using the evolutionary simulation technique for structure prediction and combining with first-principles calculations this research aims to predict the structure of bimetallic clusters Me@Xn in which the small noble metal clusters Xn (X = Au, Ag, Cu, Pd, Pt, n = 3 -20) are doped by a single metal atom Me (Me = Fe, Co, Ni, Ce, Gd, Pr, X). The geometry optimizations, binding energies, sencond differences in energy, HOMO-LUMO gaps, and magnetic moments of Me@Xn clusters are calculated in order to investigate the evolution of structures and physical properties changing with the dimension size and doping elements. To elucidate the oxidation or reduction mechanism of bimetallic clusters to small molecules, the absorption behaviors of some small molecules such as H2, CO, and O2 on some Me@Xn clusters with specific structure and higher stability are further investigated. The ultima goal of this research is to design theoretically the new Me@Xn clusters with novel optical, magnetic or catalytic properties in order to provide the important theoretical grounds and fundamental physical data for the subsequent experiments.

双金属小团簇因存在显著的量子尺寸效应、表面效应、元素协作效应等作用而呈现出独特的物理化学性质，已受到国内外学者的高度关注，但当前的实验手段仍不能足够胜任其结构和尺寸大小的精确表征。本课题拟将采用进化模拟结构预测技术，结合第一性原理计算，理论预测贵金属小团簇Xn（X = Au，Ag，Cu，Pd，Pt；n = 3-20）掺杂单个金属原子Me（Me = Fe，Co，Ni，Ce，Gd，Pr，X）的双金属团簇Me@Xn结构，进行结构几何优化、结合能、能量二阶差分、HOMO-LUMO能隙、磁矩等电子结构计算，调查团簇结构与物性参数随尺寸和掺杂元素变化的演化规律，同时对具有独特结构和较高稳定性的团簇进行H2、CO、O2等小分子吸附行为的计算研究，探讨团簇对气体小分子的氧化或还原反应的作用机理，理论设计出具有新奇光学、磁学或催化性质的新型Me@Xn团簇，为后续的的实验研究提供重要的理论依据和基础物性数据。

双金属小团簇因存在显著的量子尺寸效应、表面效应、元素协作效应等作用而呈现出独特的物理化学性质，已受到国内外学者的高度关注，但当前的实验手段仍不能足够胜任其结构和尺寸大小的精确表征。采用进化模拟结构预测技术，结合第一性原理计算，我们理论预测了贵金属小团簇Xn（X = Au，Ag，Cu；n = 3-20）掺杂单个金属原子Me（Me = Fe，Co，Ni，Gd，Dy）的双金属团簇Me@Xn 结构，进行结构几何优化、结合能、HOMO-LUMO 能隙、磁矩等电子结构计算，调查团簇结构与物性参数随尺寸和掺杂元素变化的演化规律，同时对具有独特结构和较高稳定性的团簇进行CO、O2 等小分子吸附行为和负载于g-C3N4和TiO2表面的电子结构计算研究，探讨团簇对气体小分子的氧化或还原反应的作用机理，理论设计出具有新奇光学、磁学或催化性质的新型Me@Xn 团簇，为后续的实验研究提供重要的理论依据和基础物性数据。此外，为澄清Li-B与Na-B体系的争议结构和相稳定性，我们采用从头算进化结构模拟预测了Li-B与Na-B体系的最低能量结构，并进一步通过第一性原理计算方法研究了其稳定化合物的物理性质。