Nanoarchitectural Ni-ZrO₂ Catalysts For Hydrogen Production From Catalytic Steam Reforming Of Ethanol

for energy supply and environmental protection. The application of hydrogen fuel cell with biomass as the raw materials for hydrogen production, was recogniazed as a bridge connecting the traditional fossil fuels to the renewable energies, and became one of the major motivations for the "Hydrogen Economy". Ethanol is one of the promising feedstock for its low toxicity, easy deliverability and wide availability from biomass. Among diverse h ydrogen pr oduction technologies available, s team reforming of ethanol has emerged as an attractive route for its high system efficiency in offering hydrogen rich gas over various of catalyst candidates. This paper focused on the development of nickel catalysts with high catalytic activity in ethanol steam reforming for hydrogen production via the application of nanoarchitectural design.A main reaction route of dehydrogenation of ethanol followed by decomposition of acetaldehyde into methane and carbon monoxide, and subsequently the competition of methane steam reforming and water gas shift reaction is proposed for ethanol steam reforming over the Ni/ZrO₂ catalyst.By reducing particle size of either nickel metal or zirconia oxide of the catalyst, the interaction between the metal and the oxide was strengthened and the interface area between the nickel metal and the zirconia oxide was increased, resulting in an improved catalytic activity. Comparing with monoclinic zirconia, tetragonal zirconia showed higher c atalytic act ivity t owards the water gas s hift r eaction and the removement of the surface carbon deposition, improving the catalytic activity and stability of the catalyst.The introduction of suitable amount of Al₂O₃ into the zirconia matrix leads to significant increase in the specific area of the catalyst, enhanced nickel dispersion and strengthened interaction between nickel metal and support oxide. Comparing with the Ni/ZrO₂ catalyst, althrough the surface acidity of the catalyst was increased after the introduction of Al₂O₃, the catalytic activity tests in the temperature range of 673 973 K show increased catalytic activity and stability of the Ni/10AZ catalyst.The r esults of N 2 physical a dsorption/desorption m easurement, T EM, E DX, HREELs, XRD, and H2-TPR analysis show that, nanoarchitechtural design offers a technology to p repare catalysts w ith further enriched po rosity, improved metal dispersion, enhanced resistance of nickel metal from growing up, and strengthened metal o xide in teraction. The us e of na no N iO pow ders i n t he pr eparing of nanoarchitectural nickel-based catalysts could avoid the use of hazardous reagents during t he pr eparation of ni ckel m etal na noparticles a nd s implify the p reparation process. The selection of precipitator without the production of ammonium ion during the p recipitation p rocess an d a m etal l oading of no l ess t han 15 wt% w ere recommended for the preparation of nanoarchitectural Ni-ZrO₂ catalysts. Comparing with s upported ni ckel catalysts, bot h na noarchitectural N i-ZrO₂-NA catalyst an d nanoarchitectural Ni-AZ catalyst show higher catalytic activity and stability in the temperature range of 673 973 K for hydrogen production from steam reforming of ethanol.