The electrochemical reduction of NO in alkaline solutions was investigated at gas diffusion electrodes with various metal (Ru, Rh, lr, Pd and Pt) catalysts at various NO flow rates. Reduction currents are observed at potentials more negative than 0.95 V, which increase with the decrease in potential and also with increasing gas flow rate. The faradaic efficiencies of N2O formation decrease with decreasing NO flow rate and with decrease in potential. The faradaic efficiencies of N2 formation increase with decreasing flow rate and with decrease in potential. The reduction of NO to N2 at a flow rate of 5mlmin−1 occurs selectively at potentials more negative than 0.1V; the faradaic efficiency of N2 formation is approximately 95 at Pd catalysts.
Electricity production and NO decomposition can be carried out simultaneously using an H2–NO fuel cell reactor. The faradaic efficiency of N2 formation at a flow rate of 5mlmin−1 is approximately 80 at a cell voltage of 0.25 V.