An electrochemical cell comprising: (i) an anode half-cell with an anode, (ii) a cathode half-cell with a cathode, (iii) an ion-exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode comprising a gas diffusion electrode, (iv) a gap between the gas diffusion electrode and the ion-exchange membrane, (v) an electrolyte feed inlet above the gap, (vi) an electrolyte drain beneath the gap, (vii) a gas inlet, (viii) a gas outlet, and (ix) an electrolyte holding vessel comprising an overflow connected with the electrolyte feed inlet.