Abstract:

Cu/γ-Al2O3, Ni/γ-Al2O3, and Cu-Ni/γ-Al2O3 catalysts were prepared using the deposition-precipitation method and the catalytic performances for hydrogen production during dimethyl ether steam reforming(DME SR) were investigated. The structure and surface characteristics of these catalysts were analyzed by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS), NH3 temperature-programmed desorption (NH3-TPD), temperature-programmed oxidation (TPO), and transmission electron microscopy (TEM). It was revealed that both copper and nickel were active components during DME SR and there were interactions among Cu, Ni, and γ-Al2O3. Nickel addition improved copper dispersion to obtain small copper crystallites, and strengthened the interaction between copper and γ-Al2O3 so as to prevent copper agglomeration. Copper addition also improved nickel dispersion and the smaller nickel particle size suppressed CH4 formation, which prevented coke formation. Therefore, Cu-Ni/γ-Al2O3 with superior catalytic activity and stability was obtained. During 100 h durability testing, the Cu-Ni/γ-Al2O3 maintained about 95% DME conversion and did not show obvious deactivation.

Key words: Copper, Nickel, Alumina, Dimethyl ether steamreforming, Hydrogen production, Stability