NO双分子在Cu_2O(111)面吸附与解离的理论研究  

Theoretical Studies of the Adsorption and Dissociation of Two NO Molecules on Cu_2O(111) Surface

作　　者：孙宝珍[1] 陈文凯[1] 徐香兰[1] 

机构地区：[1]福州大学化学系,福州350002

出　　处：《物理化学学报》2006年第9期1126-1131,共6页Acta Physico-Chimica Sinica

基　　金：福州大学科技发展基金(2005-XQ-03);福建省教育基金(JA03020);福建省重大专项基金(2005HZ01-2-6)资助项目

摘　　要：采用广义梯度密度泛函理论结合周期平板模型方法,在DNP基组下,研究了NO双分子在三重态和单重态两种电子组态下在Cu2O(111)完整表面的吸附情况.考虑了Cu+(NO)(NO)、Cu+(NO)(ON)及Cu+(ON)(ON)这三种构型,计算了它们的吸附能和Mulliken电荷,分析并预测了吸附后可能产生的物种.结果表明,当两个NO分子都以O端吸附在Cu2O(111)表面时即Cu+(ON)(ON)构型,N—N键长很短,只有124.4pm,吸附的两个NO分子形成了二聚体形式,这种吸附构型有利于进一步离解产生N2或N2O并形成Cu-O表面物种.The adsorption and dissociation of two NO molecules on Cu2O（111） surface have been studied with periodic slab model by DFT method using the generalized gradient approximation （GGA） with the Perdew-Burke-Emzerhof （PBE） exchange-correlation functional. Three kinds of structures, Cu^＋（NO）（NO）, Cu^＋（NO）（ON）, and Cu^＋（ON）（ON）, with singlet and triplet states, were considered. Their corresponding adsorption energies and Mulliken charges were calculated. The calculated results indicate that in the optimized Cu＋（ON）（ON） configuration, two adsorbed NO molecules form a dimeric species with a much shorter N-N bond length（about 124.4 pm）. Such a configuration contributes to the dissociation of NO to Cu-O surface species, with elimination of N2 or N2O .

关 键 词：密度泛函理论 周期平板模型 NO Cu2O(111) 吸附 二聚体 离解 

分 类 号：O647.31[理学—物理化学]