FeN_4掺杂对富勒烯催化特性调制的第一性原理研究

因其较好的稳定性和催化活性,非金属N与金属共掺杂的富勒烯(C60)作为新型氧化还原反应(ORR)催化剂受到了人们的广泛关注.采用基于密度泛函理论的第一性原理方法系统地研究了Fe N4掺杂对C60催化特性的调制规律,揭示了O_2在Fe N4掺杂的C60上的吸附和氢化特性.结果表明:(1)O_2倾向于以side-on模式吸附在Fe的顶位上,O-O键平行于C60的球切面,与Fe形成O-Fe-O三元环结构,对应的吸附能为1.48 e V.(2)O_2的氢化反应路径可以分为两条:(i)O_2先解离为O+O,然后氢化为O+OH.O_2的解离为反应的速控步,势垒为2.82 e V.(ii)O_2先氢化形成OOH结构,然后解离.氢化为反应的速控步,势垒为2.83 e V.

First-principles study on the catalysis reactivity tuning of the fullerene from FeN4 embedded

Given its good stability and activity, the nitrogen-doped and metal-coordinated Fullerene (C60) is attractive as a novel catalyst in oxygen reduction reaction (ORR). Density functional theory including dispersion-corrected (DFT-D) is performed to investigate the mechanisms of tuning of the C60 from FeN4 embedded, and the O2 adsorption and hydrogenation on the FeN4 embedded C60. It is found that: (1) O2 prefers to stay on the top of Fe with the side-on configuration and oxygen-oxygen bonds are parallel to the surface of FeN4 embedded C60, resulting in the O-Fe-O three member ring. The corresponding adsorption energy is 1.48 eV. (2) Two kinds of O2 hydrogenation paths are presented: (i) O2 decomposes into O + O and then the atomic O is hydrogenated into O + OH. The reaction rate-limiting step is the decomposition of O2 with the reaction barrier of 2.82 eV. (ii) O2 is firstly hydrogenated into OOH and subsequently decomposes into O + OH. The reaction rate-limiting step is hydrogenation of O2 with the reaction barrier of 2.83 eV.