*2.2. Catalyst Preparation*

Nickel was introduced on the supports by incipient wetness impregnation with a proper amount of Ni(NO3)2.6H2O aqueous solution to obtain 8 wt % of nickel on the catalysts. After drying at 110 ◦C for 18 h, calcination was performed in air at 650 ◦C for 4 h.
