Hydrogen production by steam reforming of ethanol over Ni-Sr-Al2O3-ZrO2 aerogel catalyst

Abstract

Ni-Sr-Al2O3-ZrO2 aerogel (NSAZ-Ae) catalyst was prepared by an one-step epoxide-driven sol-gel method and a subsequent supercritical CO2 drying method. For comparison, Ni-Sr-Al2O3-ZrO2 xerogel (NSAZ-Xe) catalyst was also prepared by a sol-gel method and a subsequent conventional evaporative drying method. NSAZ-Ae catalyst retained higher surface area and larger pore volume than NSAZ-Xe catalyst. NSAZ-Ae catalyst also showed strong interaction between active metal and support, which led to small nickel particles after the reduction. H2-TPD (temperature-programmed desorption) results revealed that NSAZ-Ae catalyst with smaller nickel particle size had higher nickel dispersion and higher nickel surface area. In addition, NSAZ-Ae catalyst showed higher ethanol adsorption capacity than NSAZ-Xe catalyst. Performance and stability of the catalyst in the ethanol steam reforming reaction was enhanced with the employment of supercritical drying as observed for NSAZ-Ae catalyst. Enhanced physicochemical property and high nickel surface area (high nickel dispersion) of NSAZ-Ae catalyst led to excellent catalytic activity and stability in the hydrogen production by steam reforming of ethanol.