Electrochemical hydrogenation of dinitrogen to ammonia on a polyaniline electrode

The fixation of molecular nitrogen (dinitrogen) to ammonia was investigated depending on applied potential, pressure and temperature on a Pt-plate coated with polyaniline (PAn) film in methanol/LiClO4/H+ solution. The reaction product was only ammonia with a maximum concentration of ca. 57 μmol L−1 after 5 h electrolysis time. Maximum current efficiency for ammonia formation was ca. 16%. The optimum film thickness was found to be 1.5 μm, N2-pressure 50 bar and an optimum electrolysis potential was only −0.12 V (NHE).