Production rates and destruction frequencies of ammonia in inductively coupled H2O/N2 and H2/N2 plasmas

Abstract

AbstractWe compared the production rates and the destruction frequencies of ammonia in inductively coupled H2O/N2 and H2/N2 plasmas. We observed that the production rates of ammonia ranged between 4 and 7 μmol/s both in the H2O/N2 and H2/N2 plasmas generated at rf powers between 100 and 160 W, corresponding to the energy cost of 23–25 mol/MJ. Almost the same production rates suggest the usefulness of H2O as the resource for hydrogenation of atomic nitrogen adsorbed on surfaces. On the other hand, the destruction frequency was 2–4 times higher in the H2O/N2 than H2/N2 plasmas. Although the H2O/N2 plasma has a drawback in the destruction frequency, the present work shows its potential for the direct synthesis of ammonia from water with skipping the production of hydrogen.