Ag-, Ce- and Ga-promoted Cu-Mg-Al hydrotalcite derived mixed metal oxides were obtained by standard coprecipitation, followed by calcination. The obtained Ag(Ce, Ga)-Cu-Mg-Al-O-x, mixed metal oxides were characterized with respect to their crystalline structure (XRD, TEM), texture (BET), surface acidity (NH3-TPD), redox properties (H-2-TPR), chemical surface composition (XPS), and tested in the selective catalytic oxidation of ammonia into nitrogen and water vapour (NH3-SCO). The loading of Ag-y-, Ce-y-, or Ga-y-Cu-3-Mg66-y-Al-29 (y=0-1) had a clear effect on the catalytic perfdrmances. For materials with low metal loadings (y <= 0.25), the redox properties determined the catalytic performances in NH3-SCO. The formation of easily reducible CuOx, played a crucial role for enhanced catalytic activity at lower temperatures, with a drop in the selectivity to N-2 at higher temperatures. Higher metal loading (y >= 0.5) led to the formation of surface and bulk copper oxide species, and other aggregated metal oxide phases, which enhanced the catalytic activity for Ag-Cu-Mg-Al-O-x, and diminished activity for Ce(Ga)-Cu-Mg-Al-O-x. (C) 2017 Elsevier B.V. All rights reserved.