The effect of the concentration of NO3 -toward the selectivity of urea is investigated. The concentration of bicarbonates is kept constant in the electrolyte (0.1 M KHCO3) and the concentration of NO3 -(1, 0.5, 0.1, 0.01, and 0.001 M KNO3) is varied. For all the above cases, the electrolyte is equilibrated with CO2 and chronoamperometry is performed at -1 V vs. RHE. Figure denotes the FEs of the products and urea current densities as the concentration of NO3 -is changed by fixing the concentration of bicarbonate. As the concentration of NO3 -is increased the urea current density increases as the function of the concentration of NO3 -. At lower concentration of NO3 -, CO is observed to a great extent. As the concentration of NO3 -is increased NH3 is observed with decreasing concentration of CO, indicating that NORR is more preferred than CO2RR. Beyond 0.1 M of NO3 -, only urea is observed and other by products such as CO, H2 and NH3 are not observed. This indicates that the concentration of NO3 -is a key parameter in deciding the selectivity of urea apart from the applied potential.