Beijing Key Laboratory of Bio-inspired Energy Materials and Devices, School of Space and Environment, Beihang University, Beijing, 100191, China.
Phys Chem Chem Phys. 2018 Nov 7;20(41):26675-26680. doi: 10.1039/c8cp05466e. Epub 2018 Oct 15.
A simple and efficient cluster model containing only seven metal atoms was proposed to investigate the oxygen reduction reaction (ORR) activity of various metal catalysts by density functional theory (DFT) calculation. The model was validated by comparing ORR volcano plots obtained from the cluster model in this work and the slab model in the literature. We then used this model to investigate the influence of the support of Ag nanoparticles on ORR activity, which is hard to describe by the slab model. The calculations revealed the binding energy of oxygen atoms on Ag/COOH-CNTs or Ag/OH-CNTs changed to 2.04 and 2.09 eV respectively, in comparison to that of Ag/CNTs (2.13 eV). As a result, the ORR current density improved to 2.24 and 1.88 mA cm at the potential of 0.7 V (vs. RHE) for Ag/COOH-CNTs and Ag/OH-CNTs respectively, in comparison to that of Ag/CNTs (1.66 mA cm). The cluster model could simultaneously reduce the computing time and make it possible to consider the influence of catalyst supports, which would provide new insight to design more effective ORR metal catalysts.
提出了一种仅包含七个金属原子的简单高效的团簇模型，通过密度泛函理论（DFT）计算来研究各种金属催化剂的氧还原反应（ORR）活性。通过比较本文团簇模型和文献中平面模型得到的 ORR 火山图验证了模型的有效性。然后，我们使用该模型研究了 Ag 纳米颗粒负载对 ORR 活性的影响，这很难用平面模型来描述。计算表明，与 Ag/CNTs（2.13 eV）相比，Ag/COOH-CNTs 和 Ag/OH-CNTs 上氧原子的结合能分别变为 2.04 和 2.09 eV。因此，Ag/COOH-CNTs 和 Ag/OH-CNTs 的 ORR 电流密度在 0.7 V（相对于 RHE）的电位下分别提高到 2.24 和 1.88 mA cm，而 Ag/CNTs 的电流密度为 1.66 mA cm。团簇模型可以同时减少计算时间，并考虑催化剂载体的影响，这为设计更有效的 ORR 金属催化剂提供了新的思路。
