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

Abstract

The steam reforming of isooctane and methylcyclohexane (MCH) was investigated over Fe- and Ni-based catalysts. FeMg/Al2O3 catalyst, effective for CH4 decomposition in the presence of O2/CO2, 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 CH4 and C2. FeMg/Al2O3 catalyst was also less active for the steam reforming of MCH than Ni systems. Modification of FeMg/Al2O3 catalyst with rhodium resulted in the increased formation of aromatic byproducts. The rate of H2 production with Ni/ZrO2 catalyst was found to be 7 times higher than that with FeMg/Al2O3. Furthermore, the stability of the Ni/ZrO2 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/ZrO2 catalyst for the reaction at 973 K remained stable after 100 hours, although below 10% decrease in the rate of H2 formation was observed. On the contrary, above 50% decrease in the rate was observed over Ni/ZrO2 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/ZrO2 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.

First-Principles Modeling of Direct versus Oxygen-Assisted Water Dissociation on Fe(100) Surfaces

“…Noble metals such as Ru [9,10], Rh [10,11], Pd [10], Ir [10][11][12][13], and Pt [10,14] are active for steam and oxidative reforming but are not preferred in conventional industrial reformers due to their high costs. This motivates studies on non-precious metal catalysts, such as Ni- [15][16][17], Cu- [18,19], Co- [20,21], and Fe- [22][23][24][25][26][27] based materials. Due to extremely low cost and high catalytic activity, Fe-based catalysts have caught great attentions.…”

Catalytic Steam Reforming Technology for the Production of Hydrogen and Syngas

“…125 They studied the effect of catalyst synthesis parameters such as method of introduction of active species, calcinations, and reduction temperatures on the catalytic performance. Murata et al 142 reported the steam reforming of isooctane and methylcyclohexane (MCH) over FeMg/Al 2 O 3 and Ni/ZrO 2 catalysts. They observed that the rate of H 2 production over Ni/ZrO 2 catalyst was seven times higher than that over FeMg/Al 2 O 3 catalyst.…”

“…The same group also evaluated the La 2 O 3 supported Ru, Rh, and Ir catalysts in the steam reforming of kerosene in the temperature range between 500 and 800 ° C. At 600 ° C and an S/C ratio of 3, Rh -and Ru -supported catalysts produced higher hydrocarbon conversions of about 95% and H 2 yield of close to 100% compared with Ir -supported catalyst, which showed only about 60% conversion and 80% H 2 yield under the same operating conditions. Murata et al 142 compared the performance of various bimetallic catalysts containing a noble metal and a base metal for the steam reforming of n -octane and MCH with noble metal -based monometallic catalysts and FeMg/Al 2 O 3 catalyst. They noted that the FeMg/Al 2 O 3 catalyst produced a higher rate of H 2 formation compared with noble metal -based supported catalysts.…”

Dramatic improvement of catalyst life by rhodium and cerium additives for Ni-based reforming catalysts

“…Our ultimate goal is to develop a catalyst that is suitable for performing ATR of sulfur-containing retail gasoline. In previous works [5] we found that a Re-modified NiSr/ZrO2 catalyst is effective in the ATR of sulfur-containing methylcyclohexane (MCH), a model compound for gasoline. However, for ATR of retail premium gasoline, which contains sulfur (<5 ppm), as well as aromatic compounds, naphthenes, and aliphatic hydrocarbons, catalyst deactivation occurred after a 30 hour-reaction at 1023 K. Thus, a catalyst with an improved resistance to sulfur will be required, even though it will be only for stationary use and not for use in vehicles.…”