摘要
采用基于第一性原理的分子动力学与量子力学相结合的方法,对CrW_2O_9团簇在MgO(001)完整表面的吸附构型、稳定性以及电子结构进行了系统的研究.研究结果表明,CrW_2O_9团簇通过Cr、W以及O原子与MgO(001)表面作用,并可能以六元环、帽状或双环结构沉积在MgO(001)表面,其中热力学最稳定的吸附构型为CrW_2O_9团簇以六元环的结构吸附在MgO(001)完整表面.吸附后,有较多的电子从表面转移到团簇,与W3O9/MgO(001)体系相比,CrW_2O_9团簇的电子态出现在MgO(001)表面的带隙中,且主要为Cr 3d轨道的贡献,这将对体系的催化性能产生显著影响.
The configuration,stability and electronic structure of CrW_2O_9 clusters deposited on the MgO( 001) surface have been investigated using first-principles molecular dynamic simulations combined with quantum mechanical calculations. The results show that,the CrW_2O_9 clusters interact with the MgO( 001) surface by Cr,W,O atoms and the CrW_2O_9 clusters assume three different structures including six-number ring,cap-shaped and dual-ring structures when deposited on MgO( 001) surface. The most stable configuration is that CrW_2O_9 cluster adsorption on the perfect MgO( 001) surface with a six-number ring. After deposition,obvious electrons are transferred from MgO( 001) surface to the CrW_2O_9 cluster. Compared with W3O9/MgO( 001) system,the states of CrW_2O_9 cluster appear in the gap of MgO( 001) surface,mainly derived from Cr 3d state,which will have significant impacts on the catalytic properties.
出处
《江西师范大学学报(自然科学版)》
CAS
北大核心
2017年第4期432-440,共9页
Journal of Jiangxi Normal University(Natural Science Edition)
基金
国家自然科学基金(21403094)
江西省自然科学基金(20142BAB216031)
江西师范大学博士启动基金资助项目