Gono Patrick, Pasquarello Alfredo
Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
J Chem Phys. 2020 Mar 14;152(10):104712. doi: 10.1063/1.5143235.
The bifunctional mechanism for the oxygen evolution reaction (OER) involving two distinct reaction sites is studied through the computational hydrogen electrode method for a set of catalyst materials including rutile TiO(110), anatase TiO(101), SnO(110), RuO(110), IrO(110), NiP(0001), and BiVO(001). The calculations are performed both at the semilocal level and at the hybrid functional level. Moreover, anodic conditions are modeled and their effect on the OER free energy steps is evaluated. The free energies of the reaction steps indicate that for specific combinations of catalysts, the limitations due to the linear scaling relationship can be overcome, leading to smaller overpotentials for the overall OER. At the same time, a detailed analysis of the results reveals a strong dependence on the adopted functional. For both functionals, it is shown that the energy level of the highest occupied electronic state can serve as a descriptor to guide the search for the optimal catalyst acting as a hydrogen acceptor. These results support the bifunctional mechanism as a means to break the linear scaling relationship and to further reduce the overpotential of the OER.
通过计算氢电极方法，对包括金红石型TiO(110)、锐钛矿型TiO(101)、SnO(110)、RuO(110)、IrO(110)、NiP(0001)和BiVO(001)在内的一组催化剂材料，研究了涉及两个不同反应位点的析氧反应（OER）的双功能机制。计算在半定域水平和杂化泛函水平上进行。此外，对阳极条件进行了建模，并评估了其对OER自由能步骤的影响。反应步骤的自由能表明，对于特定的催化剂组合，可以克服由于线性标度关系导致的限制，从而使整个OER的过电位更小。同时，对结果的详细分析揭示了对所采用泛函的强烈依赖性。对于这两种泛函，结果表明最高占据电子态的能级可以作为描述符，以指导寻找作为氢受体的最佳催化剂。这些结果支持双功能机制作为打破线性标度关系并进一步降低OER过电位的一种手段。
