Ammonia synthesis by atmospheric-pressure plasma jet at room temperature

Ammonia (NH 3 ) is extremely important as a raw material of chemical fertilizers for food production. NH 3 was produced in water irradiated with an atmospheric-pressure argon (Ar) plasma jet in air. The concentration of ammonium ions (NH 4+ ) in water was measured under different plasma irradiation time, applied voltage, and plasma irradiation distance. The concentration of formed NH 4+ increased almost in proportion to the plasma irradiation time and the applied voltage. The maximum NH 4+ concentration obtained in this study was 43.2 µM at an applied voltage of 10 kV, an Ar gas flow rate of 10 L/min, a plasma irradiation distance of 10 mm, and a plasma irradiation time of 80 min. During plasma irradiation, the water temperature was ~26 °C.