Small Dopants Make Big Differences: Enhanced Electrocatalytic Performance of MoS2 Monolayer for Oxygen Reduction Reaction (ORR) by N– and P–Doping
Small Dopants Make Big Differences: Enhanced Electrocatalytic Performance of MoS2 Monolayer for Oxygen Reduction Reaction (ORR) by N– and P–Doping
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DOI：
10.1016/j.electacta.2016.12.144
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发表时间：
2017-01
影响因子：
6.6
通讯作者：
Huiying Zhang;Yu Tian;Jingxiang Zhao;Q. Cai;Zhongfang Chen
中科院分区：
文献类型：
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作者：
Huiying Zhang;Yu Tian;Jingxiang Zhao;Q. Cai;Zhongfang Chen
设计和开发低成本、高效率的氧还原电催化剂是燃料电池大规模应用的关键。本文通过密度泛函理论（DFT）计算，探讨了在酸性介质中，N和P两种杂原子掺杂对二硫化钼（MoS2）单分子层底面氧化还原活性的影响.计算结果表明，用N或P原子取代MoS2单分子膜中的S原子可以在MoS2基底面引入高自旋密度，从而提高其对O2活化的化学反应性，并且随后的ORR步骤更倾向于通过更有效的4e途径进行。特别是N掺杂的MoS2单层膜表现出优异的ORR催化性能，其小的过电位（0.67 V）和低的能垒（0.25 eV）与Pt基电催化剂相当（甚至更低）。相比之下，P掺杂的MoS2单层的催化活性相当差，这是由于其在随后的反应中与O* 和OOH* 物种的非常强的相互作用。因此，我们预期N掺杂的MoS2单分子层是一种很有前途的单原子催化剂，在燃料电池中具有高的氧化还原效率。
The design and development of low-cost and highly efficient electrocatalysts for oxygen reduction reaction (ORR) is crucial to the large-scale commerical application of fuel cells. Herein, by means of comprehensive densty functional theory (DFT) computations, we explored the potential of the heteroatom doping (N and P) to activate the basal plane of molybdenum disulfide (MoS2) monolayer for ORR in acidic medium. Our computations revealed that substituting S in MoS2monolayer with N or P atom can introduce high spin density into MoS2basal plane, leading to its improved chemical reactivity for the O2activation, and the subsequent ORR steps prefer to proceed though a more efficient 4e pathway. Especially, N-doped MoS2monolayer exhibits outstanding ORR catalytic performance in terms of its small overpotential (0.67 V) and low energy barrier (0.25 eV), which is comparable (even lower) to those of Pt–based electrocatalysts. In contrast, the catalytic activity of P–doped MoS2monolayer is considerably poor due to its very strong interaction with O*and OOH*species in the subsequent reactions. Therefore, we expect that N-doped MoS2monolayer is a quite promising single-atom-catalyst with high efficiency for ORR in fuel cells.