A series of Co-Mn-Al mixed oxides modified with alkali metals (Li, Na, and K) were prepared from Co-Mn-Al layered double hydroxide and tested for N2O catalytic decomposition in inert gas and in the presence of oxygen. Chemical analysis, XRD, N-2 sorption, TPD-O-2 and TPD-N2O were used to characterize the catalysts. During TPD-O-2, higher amount of O-2 was desorbed from more active catalysts. The extent of O-2 inhibition related to the degree of surface coverage by oxygen. (C) 2011 Elsevier B.V. All rights reserved.