Hydrogen Production Via Ethanol Steam Reforming Over Ni/Al2O3 Catalysts: Effect of Ni Loading

Abstract

Catalytic systems play an important role in hydrogen production via ethanol reforming. The effect of Ni loading on the characteristics and activities of Ni/Al2O3 catalysts used in pure ethanol steam reforming are not well-understood. Two series of catalysts with various Ni loadings (6, 8, 10, 12, and 20 wt. %) were prepared by impregnation (IMP) and precipitation (PT) methods and were tested in reforming reactions. The catalysts were characterized by Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), temperature-programmed reduction (TPR), and scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM–EDAX). Powder XRD patterns of all the catalysts exhibited only NiO. Lower Ni loading catalysts were more efficient in H2 production, as evidenced by the finding that a 6 wt. % Ni catalyst, synthesized via the PT method, yielded 3.68 mol H2 per mol ethanol fed. The high surface area and small crystallite size of the low Ni loading catalysts resulted in sufficient dispersion and strong metal-support interactions, which closely related to the high activity of the 6 PT catalyst.