Assessment of Constant-Potential Implicit Solvation Calculations of Electrochemical Energy Barriers for H2 evolution on Pt

Theoretical estimation of the activation energy of electrochemical reactions is of critical importance but remains challenging. In this work, we address the usage of an implicit solvation model for describing hydrogen evolution reaction steps on Pt(111) and Pt(110), and compare with the `extrapolation' approach as well as single-crystal measurements. We find that both methods yield qualitatively similar results, which are in fair agreement with the experimental data. Care should be taken, however, in addressing spurious electrostatic interactions between periodically repeated slabs in the VASPsol implementation. Considering the lower computational cost and higher flexibility of the implicit solvation approach, we expect this method to become a valuable tool in electrocatalysis.