A mathematical model has been developed for the simulation of the ammonia oxidation in a reverse flow reactor. Computer simulations were carried out with a kinetic scheme, based upon elementary reaction steps. Aim was to explore the potential of a reverse flow reactor for selective oxidation of NH3 to produce either N-2, NO, or N2O via a dedicated operation procedure. Therefore, the conversion of NH3 and the selectivity toward N-2, NO, or N2O, were compared for a reverse flow operation and a steady state, once-through operation. A new operation concept of reverse flow operation in combination with a periodically lower feed concentration is proposed. The novel reactor concept shows a better performance compared to normal reverse flow operation and to steady state, once-through operation. The results indicate that reverse flow operation can be applied for manipulation of conversion and selectivity. A periodically lower feed concentration may increase the conversion, even up to levels that exceed the steady state value. (C) 2004 Elsevier Ltd. All rights reserved.