In recent years, there has been significant progress made in the modeling of electrochemical interfaces and electrocatalytic processes from first principles. Trends in the electrocatalytic activity have been addressed and understood in terms of simple, but powerful reactivity concepts (1). However, in most of the computational studies, the influence of the electrochemical environment has not explicitly been into account. Thus the role of the explicit presence of the electrolyte, the correct equilibrium electrode coverage of ions from the solution and/or the influence of varying electrode potentials on electrocatalytic processes still need to be assessed. In this contribution, recent attempts to address the equilibrium coverage of hydrogen (2,3) and halides (4) on metal electrodes will be presented. The presence of the aqueous electrolyte has been taken into account modeling water layers either implicitly through a polarizable medium (2) or explicitly in ab initio molecular dynamics runs (3). The calculations confirmed experimental observations that electrode surfaces can exhibit a high coverage - as a function of the electrode potential - of either cations or anions (see Fig. 1). The adsorption of ions can thus alter the properties of the electrode surface significantly (3). Recent attempts to include the electrochemical environment in a first-principles description of the electro-oxidation of methanol on Pt(111) will be presented. References (1) S. Wang et al., PhysChemChemPhys 2011, 13, 20760. (2) S. Sakong, M. Naderian, K. Mathew, R. G. Hennig, and A. Gross, J. Chem. Phys. 2015, 142, 234107. (3) T. Roman and A. Gross, Catal. Today. 2013, 202, 183. (4) F. Gossenberger, T. Roman, and A. Gross, Surf. Sci. 2015, 631, 17.

Considering the electrochemical environment in the first-principles modeling of electrocatalytic processes

251st National Meeting (2016)

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