A process for the selective oxidation of ammonia to nitric oxide in the presence of elemental nitrogen with minimal oxidation thereof, which comprises combining the ammonia with a predetermined amount of oxygen containing gas to give at least 1% stoichiometric excess of oxygen for the oxidation of the ammonia to nitric oxide; and passing the resulting mixture over a ceramic catalyst of the following empirical formula at an elevated temperature:W.sub.k X.sub.n J.sub.(1-k-n) ZO.sub.(3.+-.m)whereinW is Zirconium, Tin or Thorium or mixtures thereof;X is an alkaline earth metal or mixture thereof;J is Scandium, Yttrium, a rare-earth element or mixture thereof;Z is a metal of the first transition series or a mixture thereof, at least 0.01% of said metal having an oxidation state other than +3;k is a number having a value between 0 and about 0.1;m is a number having a value of from 0 to about 0.26; andn is a number having a value from 0 to about 0.51, provided when n has a value of 0, k has a value between 0 and about 0.05.