Yoo Jong Suk, Liu Yusu, Rong Xi, Kolpak Alexie M
J Phys Chem Lett. 2018 Apr 5;9(7):1473-1479. doi: 10.1021/acs.jpclett.8b00154. Epub 2018 Mar 9.
Density functional theory is employed to investigate the electronic origin and feasibility of surface lattice oxygen (O) participation during the oxygen evolution reaction (OER) on perovskites. O participation occurs via the nonelectrochemical pathway in which adsorbed atomic oxygen (O*) diffuses from the transition-metal site to the oxygen site, and then O shifts out of the surface plane to react with O* to form O-O* and a surface oxygen vacancy. The different thermodynamic driving forces of O participation on LaMO (M = Ni, Co, and Cu) are explained by the changes in the oxidation state of the transition-metal site throughout the reaction. We show that O participation on LaNiO cannot be hindered by O protonation in the OER potential range. By including the coverage effect and utilizing the implicit solvent model, we finally show that lattice oxygen mechanism is more feasible than the conventional mechanism for OER on LaNiO.
采用密度泛函理论研究钙钛矿上析氧反应(OER)过程中表面晶格氧(O)参与的电子起源和可行性。O的参与通过非电化学途径发生,其中吸附的原子氧(O*)从过渡金属位点扩散到氧位点,然后O移出表面平面与O反应形成O-O和表面氧空位。通过整个反应过程中过渡金属位点氧化态的变化,解释了O参与对LaMO(M = Ni、Co和Cu)的不同热力学驱动力。我们表明,在OER电位范围内,O质子化不会阻碍LaNiO上的O参与。通过考虑覆盖效应并利用隐式溶剂模型,我们最终表明,晶格氧机制比LaNiO上OER的传统机制更可行。