Ni(pre)/TiO2(SG) was obtained following a similar sol-gel route than for the Ni(post)/TiO2(SG) catalyst, except that the Ni(NO3)2 (equivalent to 1 wt.% of Ni) precursor was dissolved under stirring in the ethanolic solution of TTIP. After the drying step, the resulting material was calcined at 500°C for 5 h in flowing air with a ramp of 5°C/min, and finally reduced at a temperature ranging from 500°C to 700°C, with a 5°C/min ramp.