CAJ | 학술논문

采用密度泛函方法研究了Fe(100)表面Cu单层膜上CO的吸附,直接解离,氢助解离以及C-C偶合反应.相比洁净的Fe(100)表面,在Fe(100)的单层Cu膜上,CO的吸附和活化都减弱了.特别是,相比Fe(100)上CO的解离能垒1.08 eV,铜单层膜上CO解离能垒高达2.4 eV.在H原子共吸附的情况下,Fe(100)上CO解离在动力学上更容易了一些,而在Cu单层膜上,CO的解离通过形成甲酰基(CHO)大大的加快了,能垒降低到了0.92 eV,接近Fe(100)上的0.81 eV.同时,我们发现Cu单层膜上C-H键C-C键的形成比Fe(100)上能垒低,且放热量更大.
채용밀도범함방법연구료Fe(100)표면Cu단층막상CO적흡부,직접해리,경조해리이급C-C우합반응.상비길정적Fe(100)표면,재Fe(100)적단층Cu막상,CO적흡부화활화도감약료.특별시,상비Fe(100)상CO적해리능루1.08 eV,동단층막상CO해리능루고체2.4 eV.재H원자공흡부적정황하,Fe(100)상CO해리재동역학상경용역료일사,이재Cu단층막상,CO적해리통과형성갑선기(CHO)대대적가쾌료,능루강저도료0.92 eV,접근Fe(100)상적0.81 eV.동시,아문발현Cu단층막상C-H건C-C건적형성비Fe(100)상능루저,차방열량경대.
CO adsorption,CO dissociation and C-H and C-C bond-making reactions on Cu-covered Fe(100) have been computed within the framework of periodic density functional theory.Compared to the clean Fe(100) surface with strong CO activation,Cu monolayer-covered Fe( 100 ) surface has weaker CO adsorption energy,lower CO activation degree; and ultra higher CO dissociation barrier (2.4 eV).Under H co-adsorption,CO dissociation is favored kinetically on Fe(100).On the Cu-monolayer covered Fe( 100),co-adsorbed H largely facilitates CO dissociation via the formation of CHO.The energy barrier decreases to as low as 0.92 eV.It is also found that C-H and C-C bond-making reactions of Cu monolayer-covered Fe(100) surface have lower activation barriers and are more exothermic than on the clean Fe(100) surface.