合成氨铁催化剂N_2络合活化模型

The EHMO calculation of Absorbed Dinitrogen on Iron-based Catalysts for Ammonia Synthesis

采用电荷自洽推广的休克尔近似,以基态分子氮为标尺,计算了以α-Fe为主催剂的氨合成催化作用中若干种N_2 络合吸着模型和活化方式,指出N_2 在多晶铁催化剂上的离解化学吸附是氨合成的决定步骤。结果表明 N-N 键电子集居数有相当大的下降,而且N_2 主要扮演π-电子接受体的角色。

The extended Huckel method with respect of the electronic charge self-consisent was used to calculate a series of models for absorbed N2 on α-Fe as principal catalyst by various coordinated / actived modes in ammonia synthetic catalysis. It is shown that dissociated chemisorp tion of N2 on iron-based catalyst is an important rate-determining step in the synthesis of NH3 from N2 and H2. The results of calculation is also demonstrated that the electron population of N-N bond is fall largely down and N2 plays essentially the role of π-eletron acceptor.