团簇CoFe2BP的结构及催化性质

利用DFT(密度泛函理论)方法,在B3LYP/Lan12dz水平下,对Co Fe2BP团簇的二十几种可能构型进行全参数优化和相关频率计算,共获得二、四重态稳定构型各5种,对这些构型的立体结构及其能量、成键情况和催化活性等性质进行了分析,得出如下结论:(1)在Co Fe2BP团簇的各优化构型中,构型1(4)的稳定性最好,四重态的稳定性要大于二重态的,多重度对构型稳定性影响较大;(2)金属原子与非金属原子之间的成键对构型的稳定性起主要作用,其中金属原子与B原子更易成键,B、P原子之间存在近距离接触;(3)金属原子Fe和Co是Co Fe2BP团簇前线轨道的主要贡献者,Fe和Co原子是催化剂潜在的活性位;(4)具有近似平面型结构的构型4(2)和4(4)表现出良好的催化加氢活性。

Study on structure and catalytic properties of CoFe2BP cluster

More than twenty different configurations of cluster CoFe2BP with doublet and quadruplet multiple states are calculated under the B3LYP/Lan12dz level by using the Density Functional Theory(DFT)method. After the frequencies of each configuration are authenticated,five stable configurations with doublet and qua-druplet multiple states are obtained respectively. The geometric structure,energy,bonding properties and cata-lytic activity of these stable configurations are also analyzed. Conclusions are drawn as follows:(1)The con-figuration 1(4) is the most stable structure in the whole stable configurations of cluster CoFe2BP,the quadruplet multiple states stable configurations are more stable than doublet stable configuration and multiplicity affects the stability of structure;(2)The bond between metal atom and nonmetal atom play a important role in the stability of configurations. The bonds between metal atoms and B atom are easier than other bonds,B and P at-om have a close contact.(3)Three metal atoms(Fe and Co)are a major contributor to the frontier orbital of CoFe2BP cluster and Co and Fe atoms are the potential active site of catalyst.(4)The configuration 4(2) and 4 (4) that having a preferable plain-form structures put up favorable catalytic hydrogenation activity.