However, further details related to the long-term operation of equipment with sea water should be detailed in future studies due to the corrosion, a process caused by saltwater reacting to metals. Energy yield produced from both N2/sea water vapor and N2/H2 mixtures declined with the increase of input power. Ammonia synthesis from the N2/sea water vapor at the N2 input flowrate of 6.2 sccm secured a higher energy yield (2.3 g NH 3 . kW -1 . h -1 ) than that produced with greater N2 flowrates such as 12.5 sccm (2.2 g NH 3 . kW -1 . h -1 ) and 25.0 sccm (0.6 g NH 3 . kW -1 . h -1 ), as shown in (Fig. ). (Calculation details can be found in Supporting Information). Meanwhile, the highest energy yield for the synthesis of ammonia over the N2/H2 mixture was 2.2 g NH 3 . kW -1 . h -1 at a N2 flowrate of 3.1 sccm (Fig. ). These observations further validate our postulate that plasma catalytic reactions for ammonia production from N2 and sea water vapor and N2/H2 were not solely controlled by the plasma power but by the nature of the catalyst as well. The presence of a catalyst in the plasma zone appears to alter the plasma-surface reactions, resulting in plasma-catalyst synergism, and by that, promoting the ammonia production. To verify the influence of the metal active centers on ammonia synthesis from N2 and sea water vapor, this work also employed the SiO2 as a support impregnated with metals such as Ag, Cu, and Co. The catalytic performance of these catalysts is shown in Fig. . For the N2 and sea water vapor system, the presence of a metal supported on the SiO2 support did not increase the ammonia synthesis rate significantly.