The computational framework employed here provides a systematic approach for understanding the material changes from bulk to surface during the operando conditions not only from a thermodynamic perspective but also from a kinetic standpoint. The simulations point to an OD-Cu oxygen content at zero electric potential vs SHE highly depends on the pH, Cu2O is reduced to Cu under strongly acidic conditions, while Cu2O is stable under strongly basic conditions. Under near neutral conditions at zero electric potential vs SHE, the Cu2O with specific surface area of 0.146 Å -1 retains 15 at.% oxygen.