铂钌团簇及电荷对甲醇活性的理论研究  

A Theoretical Study on the Reactivity and Charge Effect of Pt Ru Clusters toward Methanol Activation

作　　者：赵俊凤[1] 孙小丽[1] 黄旭日[1] 李吉来[1] 

机构地区：[1]吉林大学理论化学研究所,长春130023

出　　处：《物理化学学报》2016年第5期1175-1182,共8页Acta Physico-Chimica Sinica

基　　金：国家重点基础研究发展规划项目(973)(2012CB932800);国家自然科学基金(21103064;21473070)资助~~

摘　　要：采用密度泛函理论(DFT)对钌掺杂的铂团簇阳离子([Pt_nR_ m]^(+),m+n=3,n≥1)活化甲醇C―H和O―H键反应进行了理论研究;探讨了电荷对[Pt_nRu _m]团簇反应活性的影响。电荷分析表明:(1)[Pt_3]^(+)团簇中正电荷在三个Pt原子上均匀分布;掺杂Ru原子后,正电荷主要分布在Ru原子上;(2)首先活化C―H键时[[Pt_nR_ m]^(+)的反应活性比[Pt_nRu_m]明显提高;首先活化O―H键时只有[Pt_3]^(+)比[Pt_3]团簇的反应活性有明显提高。本研究可为金属团簇调控的C―H键和O―H键的活化提供更深入的理解。Density functional theory（DFT） calculations were performed to gain mechanistic insight into the methanol C―H and O―H bond activations mediated by ruthenium-doped platinum cationic clusters [PtnRum]^＋（m ＋ n = 3, n ≥ 1）. The charge effect on the reactivity has been elucidated. Calculations show that positive charge is evenly distributed on the three Pt atoms of the [Pt3]^＋cluster, while in the Ru-doped clusters, positive charge is mainly distributed on the Ru atom（s）. The reactivity of [Pt n Ru m]＋is significantly greater than neutral[PtnRum] during the initial C―H bond cleavage, while only [Pt3]^＋exhibits greater reactivity than [Pt3]^＋ in the course of O―H bond cleavage. This study may aid in deeper understanding of C―H/O―H bond activations mediated by metal clusters.

关 键 词：密度泛函理论 甲醇 键活化 电荷 反应活性 

分 类 号：O641.1[理学—物理化学]