The dependence of electronic potential on electrocatalytic property were investigated by using a uniform charge background to compensate the surface excess charges. The aqueous solvent environment was described under implicit solvent models by the VASPsol code. The relative permittivity was set to 80 to simulate aqueous electrolytes. The effective surface tension parameter in VASPsol was 0 to neglect the cavitation energy contribution. The linearized Poisson-Boltzmann model with a Debye length of 3.0 Å simulates the compensating charge. In order to understand the reaction mechanism at various electrode potentials, the potential applied to the electrochemical interface was simulated by introducing or removing electrons (Δn) to the supercell.