Computational ab-initio investigations with Density Functional Theory (DFT) have provided the basis for the mechanistic understanding of several electrochemical reactions, such as the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), electrochemical CO 2 reduction (CO 2 R), hydrogen evolution reaction (HER). While reaction thermodynamics for reactions involving protonelectron transfers are readily captured by the computational hydrogen electrode, accurately determining activation energies for these reactions remains a challenge.