Selective oxidation of ammonia to NO was studied in a dense mixed ion electron conducting Ba0.5Sr0.5Co0.8Fe0.2O3-delta membrane reactor, which integrates the separation and catalytic reaction process in a single reactive separation unit. The influence of the temperature and feed concentration on the membrane reaction performance were investigated in detail Under reaction conditions, the oxygen permeation flux through the dense membrane increases with increasing temperature and ammonia flow rate The lower temperature and ammonia concentration can favor the formation of NO, in which higher catalytic performance is obtained, suggesting that the membrane reactor operation is much beneficial for selective oxidation of ammonia. (C) 2009 Elsevier B.V. All rights reserved