Graphyne nanotubes as electrocatalysts for oxygen reduction reaction: the effect of doping elements on the catalytic mechanisms
Graphyne nanotubes as electrocatalysts for oxygen reduction reaction: the effect of doping elements on the catalytic mechanisms
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DOI：
10.1039/c5cp05350a
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发表时间：
2015-01-01
影响因子：
3.3
通讯作者：
Chen, Xin
中科院分区：
文献类型：
--
作者：
Chen, Xin
采用密度泛函理论（DFT）方法研究了掺杂单壁γ-石墨炔纳米管（GNT）的氧还原反应（ORR）活性及其机理.四个最常用的掺杂元素，N，B，P和S原子，被用来研究掺杂效果。计算结果表明，不同元素掺杂的GNT会导致不同的ORR催化机理。N-和B-GNT催化的ORR均由O-2的端对吸附引发，并通过O-H2O解离机制完成，而P-GNT上的ORR由O-2的桥吸附引发，并通过O-2解离机制完成。通过对ORR物种的吸附能和ORR途径的形貌分析，预测了掺杂GNT的催化性能依次为N-GNT > B-GNT > P-GNT > S-GNT。电子结构分析表明，掺杂GNT的高ORR活性与合适的HOMO能级和HOMO-LUMO能隙直接相关。
The detailed density functional theory (DFT) calculations have been carried out to study the oxygen reduction reaction (ORR) activity and the mechanism on doped single-walled gamma-graphyne nanotubes (GNTs). Four of the most commonly used doping elements, N, B, P, and S atoms, were used to investigate the doping effects. The calculated results indicate that doping GNTs with different elements could lead to different ORR catalytic mechanisms. The ORR catalyzed by both N- and B-GNTs is initiated by the end-on adsorption of O-2 and is completed via an O-H2O dissociation mechanism, while the ORR on the P-GNT is initiated by the bridge adsorption of O-2 and is completed via an O-2 dissociation mechanism. The predicted catalytic performance of the doped GNT would decrease in the sequence N-GNT > B-GNT > P-GNT > S-GNT, based on the analysis of adsorption energies of ORR species and landscapes of ORR pathways. Electronic structure analysis shows that the high ORR activity of doped GNTs is directly related to the suitable HOMO levels and HOMO-LUMO energy gaps.