Oxidative dehydrogenation of propane using Ni-Mg-Al mixed oxide catalysts from hydrotalcite-type precursors

Layered double hydroxide (LDH) precursors containing Ni2+, Mg2+ and Al3+ ions in the layers and terephthalate as an interlayer compensation anion were prepared. LDHs were synthesized with an Al/(Al + Ni + Mg) ratio = 0.5, varying the Ni/Mg ratio. These compounds were calcined, thus obtaining the catalysts, mixed oxides of NiMgAl. The precursors were characterized by XRD, TGA, FTIR and ICP; the catalysts were analyzed by XRD, volumetry of N-2 and TPR. The results indicated that the hydrotalcite type materials were successfully obtained, where all metals were incorporated, and the Ni/Mg ratio was higher than the nominal one. The calcined precursors are constituted by mixed oxides with NiO phase. The catalysts were tested in the oxidative dehydrogenation of propane (ODHP). The propene yield was relatively high, and an optimum of the activity and selectivity were found for experimental Ni/Mg ratio between 0.65 and 0.71.