Hydrogen Production from Steam Reforming of Hydrocarbons over Alkaline-Earth Metal-Modified Fe- or Ni-Based Catalysts

The steam reforming of isooctane and methylcyclohexane (MCH) was investigated over Fe- and Ni-based catalysts. FeMg/Al 2 O 3 catalyst, effective for CH 4 decomposition in the presence of O 2 /CO 2, was active for steam reforming of isooctane, being a little easier to cause C−C bond cleavage than MCH, but the rate of hydrogen production was insufficient, although the rate was only slightly improved by Rh modification, due to raised formation of CH 4 and C2. FeMg/Al 2 O 3 catalyst was also less active for the steam reforming of MCH than Ni systems. Modification of FeMg/Al 2 O 3 catalyst with rhodium resulted in the increased formation of aromatic byproducts. The rate of H 2 production with Ni/ZrO 2 catalyst was found to be 7 times higher than that with FeMg/Al 2 O 3 . Furthermore, the stability of the Ni/ZrO 2 catalyst was found to be improved by the addition of alkaline-earth metals into the catalyst (M/Ni = 1:2 wt ratio). In particular, the addition of Sr was the most effective and the activity of NiSr/ZrO 2 catalyst for the reaction at 973 K remained stable after 100 hours, although below 10% decrease in the rate of H 2 formation was observed. On the contrary, above 50% decrease in the rate was observed over Ni/ZrO 2 catalyst, after 100 hours. This Sr effect, possibly, could be associated with the formation of mixed oxides consisting of Sr and Zr (or Ni). The NiSr/ZrO 2 catalyst was also effective for the steam reforming of model gasoline, which contained organic mixtures with different reforming reactivities such as naphthenes, aromatics, and n - and iso-paraffins.