Solvation Effects for Oxygen Evolution Reaction Catalysis on IrO2(110)

Joseph A. Gauthier, Colin F. Dickens, Leanne D. Chen, Andrew D. Doyle, Jens K. Nørskov
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Journal of Physical Chemistry C

We study the electrochemical interface between rutile IrO2(110) and water to investigate how the inclusion of an explicit solvent influences the stabilities of adsorbed intermediates in the oxygen evolution reaction. Solvent is modeled by explicit nondissociated water molecules, and their structure is determined by a global optimization method. We find that the inclusion of an explicit solvent can significantly affect the geometry of adsorbed intermediates, changing from an interaction with the surface to an interaction with the water bilayer. These water structures consist of stacked octagonal sheets in an ordered network. Solvent stabilization is pronounced for adsorbed *OH and *OOH, which are capable of donating hydrogen bonds. We find little to no change in adsorbate binding energy as the number of layers of solvent is increased from 1 to 3, suggesting a single water bilayer is sufficient to describe the system. With either *O or *OH coadsorbates, the energetics of the reaction pathway are relatively unchanged with the inclusion of explicit solvent.

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