钴原子催化活化乙烷的反应机理

Reaction Mechanism of the Activation of Ethane via Cobalt Atom Catalysis

采用密度泛函理论B3LYP方法分别在两种不同基组水平上,研究了Co原子催化乙烷反应的反应机理,优化了反应过程中各反应物、中间体、过渡态和产物的构型,并在同一水平上计算了反应中各驻点的振动频率,运用自然键轨道理论(NBO)方法分析了各物质的成键情况和轨道间相互作用.在两种不同基组水平上研究所得的反应历程及相应的能量变化趋势是一致的,其活化过程可分为C—C键活化及C—H键活化,分别释放出CH4和H2,反应速控步骤的活化能后者较前者低,因此,C—H键的活化较C—C键活化容易进行.

The reaction mechanism of the activation of ethane via cobalt atom catalysis was investigated by DFT method at two different basis sets at the temperature of 500 K. The geometries and vibration frequencies of reactants, intermediates, transition states, and products were calculated. In addition, the bonding circumstances and orbital interactions were analyzed by natural bond orbital （NBO）. The results of two different levels indicated that the mechanism and the corresponding energy changing trend were consistent. The activation process could be divided into C-C bond activation and C-H bond activation, and the C-H bond activation was easier than the C-C bond activation.