【摘要】 开发高效、低成本的电化学反应催化剂是可再生能源技术研究的热点之一.本文采用密度泛函理论（DFT）系统地研究了grap-N,sp-N（Ⅰ）和spN（Ⅱ）三种位置的氮掺杂对不含金属的石墨炔（GDY）氧还原电催化剂性能的影响.研究表明,GDY中掺杂的氮原子通过活化其相邻的碳原子,可以显著提高GDY的氧气（O₂）吸附活性.采用自由能图描述电化学氧还原反应（ORR）的解离（dissociation）和结合（association）机制.结果表明,在大多数底物上结合机制比解离机制能提供更高的ORR起始电位.其中, sp-N（Ⅱ）掺杂GDY的理论起始电位为0.76 V,表现出最高的ORR电催化活性.本文为不含金属的N掺杂GDY的电化学ORR机理提供了原子水平的理解.更多还原

【Abstract】 The development of highly active and low-cost catalysts for electrochemical reactions is one of the most attractive topics in the renewable energy technology. Herein, the site-specific nitrogen doping of graphdiyne（GDY） including grap-N, sp-N（Ⅰ） and sp-N（Ⅱ） GDY is systematically investigated as metal-free oxygen reduction electrocatalysts via density functional theory（DFT）. Our results indicate that the doped nitrogen atom can significantly improve the oxygen（O₂） adsorption activity of GDY through activating its neighboring carbon atoms. The free-energy landscape is employed to describe the electrochemical oxygen reduction reaction（ORR） in both O₂ dissociation and association mechanisms. It is revealed that the association mechanism can provide higher ORR onset potential than dissociation mechanism on most of the substrates. Especially, sp-N（Ⅱ） GDY exhibits the highest ORR electrocatalytic activity through increasing the theoretical onset potential to 0.76 V. This work provides an atomic-level insight for the electrochemical ORR mechanism on metal-free N-doped GDY.更多还原