Nanoarchitectured Ni-ZrO2 Catalysts for Hydrogen Production From Steam Reforming of Ethanol
- Type: Conference Presentation
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Hydrogen has been considered as an important alternative energy vector and a bridge to a sustainable energy future. Production of hydrogen efficiently and economically from renewable sources, however, remains a challenge. Among diversified hydrogen production technologies, steam reforming of ethanol has been considered as an attractive route for the low toxicity, easy deliverability, and widely availability of bioethanol. This work focuses on the design of nanoarchitectural Ni-ZrO2 catalysts with high activity in ethanol steam reforming.
The use of nanograined NiO to prepare nanoarchitectural Ni-ZrO2 catalysts could avoid the use of hazardous reagents during the preparation of nickel metal nanoparticles and simplify the preparation process. The presence of ammonium ion during the precipitation of zirconia precursor led to the production of ZrO2 species with active sites catalyzing the dehydration of ethanol, thus lowering the catalytic activity and hydrogen yield. However, we have successfully shown that the introduction of Al2O3 into the zirconia matrix (Ni-AZ) could greatly improve specific area of the catalyst, the dispersion of nickel metal and catalytic activity and stability. The presence of Al2O3 could also effectively block active sites for dehydration of ethanol. The nanoarchitectured Ni-AZ catalyst yielded high activity in both water gas shift reaction as well as the steam reforming of ethanol, at the temperature range of 673-973 K. CO2, CO and CH4 were detected as the only byproducts even at low temperature (e.g., 673 K). Yield of hydrogen and selectivities of carbonaceous products were all close to the thermodynamic equilibrium temperatures investigated.