Hydrogen production from ethanol steam reforming over Ni/SiO2 catalysts: A comparative study of traditional preparation and microwave modification methods

Four silica-supported nickel catalysts with Ni content of 10 wt% were prepared by impregnation and coprecipitation methods with or without microwave-assisted calcination. The prepared catalysts were characterized by some techniques (BET, XRD, TEM, XPS, H-2-TPR, etc.) and evaluated with respect to steam reforming of ethanol (SRE) for hydrogen production. The results show that the prepared Ni/SiO2 catalysts are all very active and selective for SRE. The high activity of the four catalysts may benefit from their high specific areas and the good dispersion of active components on the carrier. The rate of carbon deposition decreases with reaction temperature especially below 450 degrees C. The maximum hydrogen yield of 4.54 mol H-2/mol EtOH-reacted can be obtained over the Ni/SiO2 catalyst by the microwave-assisted coprecipitation method at a reaction temperature of 600 degrees C, EtOH/H2O molar ratio of 1:12, liquid hourly space velocity of 11.54 h(-1) and time on stream within 600 min. The Ni/SiO2 catalysts with microwave modification exhibits better performances of hydrogen production, stability and resistance to carbon deposition than that without microwave modification preparation, which is mainly attributed to that the microwave-assisted treatment can decrease the catalyst acidity and enhance the interaction between metal support. Copyright (c) 2013 John Wiley & Sons, Ltd.