H2在Al12X (X=Al, Ni, Cu)团簇表面解离吸附的第一性原理研究
The first-principles study of the dissociative adsorption of H2 on the surface of Al12X (X=Al, Ni, Cu) clusters

以Ni和Cu原子中心替换的二十面体Al12X(X=Ni、Cu)团簇为基体、采用密度泛函理论系统计算研究了H原子及H2分子在团簇表面的吸附，并对比了纯Al13团簇对H及H2的吸附，结果表明：相对于纯Al13中H原子的桥位吸附、掺杂团簇Al12X(X=Ni、Cu)中H原子均吸附于团簇顶位；论是吸附H原子还是H2分子，Al12Ni的几何结构均发生大的畸变；相较H2在纯Al13团簇表面的解离吸附，H2在掺杂团簇Al12X(X=Ni、Cu)表面的解离反应过程中反应能均增大、势垒均降低，这表明掺杂团簇Al12X(X=Ni、Cu)相较纯Al13团簇更有利于H2解离吸附的发生。
Based on the icosahedral Al12X (X= Ni, Cu) clusters with the doped atoms in the center, the adsorption of H atom and H2 molecule on the surface of these clusters are systematically investigated by using the density-functional theory calculations, and the obtained results are compared with that of the adsorption of H and H2 on the pure Al13 cluster. Our results show that: Compared to the bridge site of the H atom on pure Al13, H adsorbs on the top site of each of the Al12X (X=Ni、Cu) clusters; The geometric structure of Al12Ni is greatly distorted in the adsorption of either a hydrogen atom or a H2 molecule. For the comparison of the dissociative adsorption of H2 on the surface of pure Al13 cluster, the reaction energies all increase and the potential barriers all decrease in the dissociation reaction processes of H2 on the surfaces of the doped Al12X (X= Ni, Cu) clusters, which implies that the doped Al12X (X= Ni, Cu) clusters are more favorable for the occurrence of the dissociative adsorption of H2 than the pure Al13 cluster.