Cyclohexane Dehydrogenation over Wet-Impregnated Ni on Al₂O₃−TiO₂ Sol−Gel Oxides

The effect of support composition, metal loading (∼10 and ∼20 wt %), and reduction temperature (573, 673, and 773 K) on the cyclohexane dehydrogenation activity of a series of nickel catalysts supported on Al2O3 and the corresponding mixed oxides with TiO2 at two compositions (Al/Ti = 2 and 25) were investigated. Under the studied conditions, benzene was the only product detected. TiO2 at low concentration (∼6 wt %, AT25) in the material of lower Ni loading (∼10 wt %) reduced at 773 K improved dehydrogenating properties. In contrast, a strong metal−support interaction (SMSI) effect was apparent after reduction at that temperature for the catalyst of similar Ni concentration supported on the equimolar binary oxide (AT2). However, this support promoted enhanced activity in samples of increased nickel loading (∼20 wt %) reduced at moderate conditions (673 K).