摘要
基于密度泛函理论的第一性原理和平板模型构造了最稳定的O2/CaO(001)表面,通过优化Se和SeO2在此表面可能的初始吸附结构得到最佳吸附构型,分析了Se原子在O2/CaO(001)表面向SeO2的转化。结果表明,Se原子在O2/CaO(001)表面的稳定吸附构型主要有两种,即O-Se-O和O-O-Se基团,其中,O-O-Se基团的Se终端具有一定化学活性;Se在O2/CaO(001)表面向SeO2转化所需反应能垒小于均相条件下生成SeO2所需反应能垒,表明CaO不仅作为吸附剂,也能促进Se向SeO2的转化;SeO2分子在O2/CaO(001)表面发生化学吸附时,吸附基底的部分价电子转移至SeO2分子轨道中。
O2/CaO(001)surface with the lowest energy was built by using the slab model and the first-principles method based on density functional theory.A series of possible adsorption configurations were optimized to get the adsorption geometries with the lowest energy for selenium(Se)and SeO2 on the O2/CaO(001)surface and the conversion of Se to SeO2 on the CaO(001)surface was then investigated.The results indicate that there are two adsorption configurations for Se atom on the O2/CaO(001)surface,viz.,O-Se-O and O-O-Se groups;therein the Se terminal in O-O-Se group has a certain chemical activity.The reaction energy barrier for the heterogeneous conversion of Se and O2 to SeO2 is less than that for the homogeneous conversion,which means that CaO can not only act as an adsorbent,but also promote the conversion of Se to SeO2 as a catalyst;certain valence electrons in adsorption substrate are transferred to the orbits of SeO2 molecule when SeO2 molecule was adsorbed on the O2/CaO(001)surface.
作者
邢佳颖
王春波
张月
邹潺
XING Jia-ying;WANG Chun-bo;ZHANG Yue;ZOU Chan(School of Energy,Power Engineering and Mechanical Engineering,North China Electric Power University,Baoding 071003,China)
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2019年第8期993-999,共7页
Journal of Fuel Chemistry and Technology
基金
山西省重点研发(社会发展)计划(201803D31027)资助~~
