Catalytic synthesis of ammonia using vibrationally excited nitrogen molecules: Theoretical calculation of equilibrium and rate constants

The dissociation of nitrogen is the rate-limiting step in the catalytic synthesis of ammonia. Theoretical calculations have shown that the dissociative sticking probability of molecular nitrogen on catalytic active metal surfaces is enhanced by orders of magnitude when the molecules are vibrationally excited to states with quantum numbers 3-10. The rate and equilibrium constants for the process using vibrationally excited nitrogen molecules are calculated and expressions for the reaction rates are derived. A comparison with the ordinary process, where the nitrogen molecules are in the vibrational ground state, shows a great potential for a significant improvement of the yield in the process.