O_2和CO在Co_2B_2/TiO_2和Co_2B_2Pt/TiO_2表面吸附的密度泛函研究  

Density Functional Study of O_2 and CO Adsorption on Co_2B_2/TiO_2 and Co_2B_2Pt/TiO_2 Surfaces

作　　者：曾庆松[1] 陈文凯[1] 戴文新[2] 李奕[1] 丁开宁[1] 

机构地区：[1]福州大学化学系,福建福州350108 [2]福州大学化学化工学院光催化研究所,福建福州350002

出　　处：《催化学报》2009年第12期1209-1214,共6页

基　　金：国家自然科学基金(90922022;10676007;20773025);福建省高等学校新世纪优秀人才计划(HX2006-103);福建省教育厅科技项目(JA08019);华中科技大学煤燃烧国家重点实验室开放基金(FSKLCC0814)

摘　　要：采用密度泛函理论探讨了TiO2表面负载Co2B2和Co2B2Pt合金簇可能的负载构型.结果表明,Co2B2和Co2B2Pt合金簇倾向于以两个Co的形式负载在两个氧上.态密度分析发现,负载后,Co2B2合金簇中部分Co原子和B原子成键加强,Co2B2Pt合金簇中Pt原子和B原子成键也加强,形成新的轨道.CO和O2在Co2B2/TiO2和Co2B2Pt/TiO2表面吸附的结果表明,Co2B2Pt/TiO2催化氧化CO性能的提高是由于Pt原子提高了Co2B2合金簇吸附CO和O2的能力.The possible models of Co2B2 and Co2B2Pt alloy clusters supported on TiO2 surface were studied by the density functional theory. The geometrical optimized results indicated that Co2B2 and Co2B2Pt alloy clusters preferred to be bound on the top of the two O atoms of TiO2 with two Co atoms. By analyzing the partial density of states for Co2B2 and Co2B2Pt alloy clusters, it was shown that the bonding interaction between partial Co and B is enhanced in the Co2B2 system. For the Co2B2Pt system, the bonding interaction between Pt and B is also enhanced. In these systems, new molecular orbitals have formed after Co2B2Pt alloy clusters were supported on TiO2 surface. Comparing the results of CO and 02 adsorption on PtCo2B2/TiO2 and Co2Bz/TiO2 surfaces, it was concluded that the promotion of CO and 02 adsorption on the Co2B2 is due to the Pt atoms onto the cluster.

关 键 词：二氧化钛 非晶态合金 密度泛函理论 氧气 一氧化碳 吸附 

分 类 号：O643.32[理学—物理化学]