Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 35: Solid-Liquid Interfaces: Reactions and Electrochemistry - Theory I
O 35.2: Vortrag
Dienstag, 21. März 2017, 12:30–12:45, HSZ 101
Quantum Chemistry of the Oxygen Evolution Reaction on Transition Metal Oxides — •Craig Plaisance1, Rutger van Santen2, and Karsten Reuter1 — 1Technische Universität München, Germany — 2Technische Universiteit Eindhoven, The Netherlands
Density functional theory (DFT) is used to examine the changes in electronic structure that occur during the oxygen evolution reaction (OER) on a model oxide catalyst containing different 3d transition metal cations (Cr, Mn, Fe, Co, Ni). Active sites identified in previous work [1] consisting of both one and two redox-active metal centers were examined. For all sites, the important water addition step was determined to occur by the transfer of two holes from the metal cation(s) to the O-O antibonding orbital of the resulting hydroperoxo. Of the sites examined, Fe was found to have the most efficient single-center site while Co was found to have the most efficient dual-center site. In line with our previous work on Co oxide [2], the activity of an active site is seen to be related to the energy required to localize holes on the oxygen species participating in the reaction, calculated with a constrained-orbital DFT method we have developed. The hole-localization process is further analyzed in terms of screening and changes in metal-oxygen hybridization to identify how the unique electronic structures of Fe and Co lead to their superior performance for the OER.
[1] Plaisance, C.P., van Santen, R.A., J. Am. Chem. Soc. 2015, 137, 14660-72. [2] Plaisance, C.P., Reuter, K., van Santen, R.A.; Faraday Discuss. 2016, 188, 199-226.