用第一性原理研究应变和Pt边缘掺杂对石墨烯氧还原能力的影响

Effects of Strain and Pt-Doped on Oxygen Reduction Reactionof Graphene Based on the First Principles Method

采用基于密度泛函理论的第一性原理方法,通过计算Pt边缘掺杂石墨烯的形成能,确定了Pt的最佳掺杂位点,并研究了引入应变前后Pt掺杂石墨烯氧还原反应的催化性能。结果表明,引入应变后石墨烯基底吸附O_(2)的结构是稳定的;随着压应变的引入,费密面附近的态密度峰值向价带移动,促进了Pt边缘掺杂石墨烯作为燃料电池阴极氧还原反应电催化剂的电子转移,有利于催化反应的进行;当引入压应变为6.1%时,Pt边缘掺杂石墨烯的催化性能最佳。

The first principles method based on density functional theory is used to calculate the formation energy of Pt-doped graphene,and the optimal doping site of Pt atom in graphene is determined.The catalytic performances of Pt-doped graphene for oxygen reduction reaction(ORR)before and after introducing a compressive strain are studied.The results show that the structure of O_(2) adsorbed on graphene substrate is stable after the introduction of the strain,the compressive strain drives the states in conduction band move close to the Fermi level,which facilitates charge transfer during ORR and finally promotes the ORR performance of the Pt single atom catalyst.It is also found that when the compressive strain is 6.1%,the Pt-doped graphene has the most active catalysis performance for ORR.