第一性原理研究O2在CrN4掺杂石墨烯上的氢化

掺杂是调制graphene催化特性的有效方法. 掺杂的Graphene, 因其具有对氧还原反应具有较高的活性, 而作为一种新型高效质子交换膜燃料电池阴极材料. 采用包含色散力校正的第一性原理的密度泛函理论方法(DFT-D)系统的研究了O2在CrN4掺杂的Graphene上的吸附和氢化特性. 结果表明: (1) O2倾向于以side-on模式吸附在Cr顶位, 形成O-Cr-O三元环结构, 吸附能为1.75 eV; (2) O2在CrN4-Gra上更倾向于直接分解成O+O, 并进一步氢化为O+OH, 反应的限速步为O2的分解, 相应的反应势垒为0.48 eV.

First-principles study on the hydrogenation of the O2 on CrN4 embedded Graphene

Doping is a useful method to modulate the catalytic properties of graphene. Doped graphene, for its high oxygen reduction reaction activity, is a new and efficient cathode material of proton exchange membrane fuel cell. The O2 adsorption and hydrogenation properties on the CrN4 doped graphene are investigated from the dispersion-corrected density functional theory (DFT-D) method. It is found that: (1) O2 prefers to stay on the top of the Cr with the side-on configuration, forming the O-Cr-O three member ring; (2) the direct decomposition of O2 into O + O on the CrN4-Gra is preferable, and the atomic O is subsequently hydrogenated into O + OH. The corresponding reaction rate-limiting step is the decomposition of the O2 with the reaction barrier of 0.48 eV.