Affordable Estimation of Solvation Contributions to the Adsorption Energies of Oxygenates on Metal Nanoparticles

Federico Calle-Vallejo (1) , Rodrigo F. de Morais (2) , Francesc Illas (1) , David Loffreda (2) , Philippe Sautet (2)

1 IQTCUB - Institut de Química Teòrica i Computacional
2 LC - Laboratoire de Chimie - UMR5182

Electrocatalysts are mainly characterized by their intrinsic adsorption properties. However, the observed electrocatalytic activity ultimately results from the interplay between such properties and various additional interactions within the electrified solid–liquid interface. One of such phenomena is solvation, which can substantially affect the stability of adsorbates. The incorporation of solvation in computational electrocatalysis models can be fully implicit (inaccurate for H-bonded adsorbates), fully explicit (challenging computation of free energies), or embedded. Here, we show that without any need for explicit or implicit media, a microsolvation approach with just three water molecules captures the contribution of co-adsorbed water to the adsorption energies of *OH and *OOH (two important adsorbates for oxygen reduction) on platinum nanoparticles of various sizes. The approach enables an accurate yet inexpensive explicit modeling of solvent–adsorbate interactions in nanoparticles and the calculation of solvation corrections, estimated as −0.59 ± 0.14 and −0.47 ± 0.13 eV for *OH and *OOH adsorption on Pt, respectively.

Domaines: Chimie théorique et/ou physique; Chimie de coordination; Matériaux

Federico Calle-Vallejo, Rodrigo F. de Morais, Francesc Illas, David Loffreda, Philippe Sautet. Affordable Estimation of Solvation Contributions to the Adsorption Energies of Oxygenates on Metal Nanoparticles. Journal of Physical Chemistry C, 2019, 123 (9), pp.5578-5582. ⟨10.1021/acs.jpcc.9b01211⟩. ⟨hal-02119986⟩