Patent ID: 8178068

Claim:
A process for the oxidation of ammonia comprising passing a feed gas comprising a mixture of a source of ammonia together with a source of oxygen over a catalyst, and operating at a temperature from 700 to 1000° C., wherein the feed gas is passed over a first stage catalyst for ammonia oxidation comprising a high surface area platinum group metal catalyst to achieve a conversion of 20 to 99% of the ammonia and yield a first stage product comprising nitrogen oxides, oxygen and unreacted ammonia, and then passing the first stage product over a second stage catalyst for ammonia oxidation, to complete ammonia oxidation, wherein the second stage catalyst is also effective as a N 2 O destruction catalyst, and yield a second stage product comprising negligible amounts of unreacted ammonia and N 2 O present in an amount of less than 500 ppm wherein the second stage catalyst comprises pellets or extrudates of a catalyst selected from the group consisting of LaCoO 3 in which partial substitution up to 20 mole % of the La has been made by Sr or Ce, or partial substitution up to 50 mole % of the Co has been made by Cu; Co 3 O 4 supported on alumina, thoria, ceria, zinc oxide or calcium oxide; and Co 3 O 4 promoted by rare earth elements or thorium.