Supported Ni catalysts with low metal loadings prepared by impregnation of α-alumina with nickel acetylacetonate (Ni(acac) 2 ) have been studied by temperature-programmed reduction (TPR). The effect of the metal loading (between 0.4 and 1.7 wt%), washing and drying, and calcination temperature on the reduction profile, temperature of maximum reduction (T M ), and H 2 /Ni ratio has been investigated. Metal–support interactions already exist at the impregnation step. The decomposition–reduction products of the organic moiety perturbing the TPR profiles and H 2 consumptions were suppressed when drying was done at 250°C. Two distinct metal species could be distinguished according to the calcination temperature. The one withT M values ≤615°C occurred at calcination temperatures ≤400°C, whereas at 600°C and above, a second species was characterized byT M values of 900°C and higher. The two species existed in different proportions in the solids calcined above 400°C and below 600°C. Some indication supported the formation of a nickel aluminate spinel-type phase when the solid was calcined at 600°C and above accounting for the high temperatures needed to reduce nickel oxide.