Effect of the preparation method on carbon behavior and hydrogen selectivity during gasoline steam reforming over nano-Al2O3 catalysts

Author(s): Dalia R.Abd El-Hafiz, Mohamed A.Ebiad, Radwa A.El-Salamony

Hydrogen generation from gasoline is essentiallyone of the critical technologies for the commercializationof small-scalefuel cells auxiliary/backup power systems, so catalysts suitable for steamreforming of gasoline are desperatelyneeded.So, in thiswork, the influence ofmetal type (Ni and Co) and preparationmethod (Co-precipitation and impregnation) on catalytic steamreformingof gasoline over nano-Al2O3 catalystswas studied at different reaction temperature (500-800oC). The structure and surface properties of the catalysts before and after reactionwere tested by different characterization techniques such as TGA, XRD,TPR,HRTEM,BETsurface areas and ramman spectroscopy. Results showthat, the products distribution is dependent on both preparationmethod and metal type, onNi/Al2O3 catalysts carbon product and methane is the major product, CO2 and CO is much less than the value ofH2. The ratio of CO2/(CO+CO2) represents theCOconversion (XCO) for theWGS reaction, lower temperatures favor theWGS reaction on all of the prepared catalysts.On the other handwe can showthatNi catalysts favorWGS reactionmore than that ofCo catalyst.AlthoughmaximumH2 selectivity (70%) is reached at 800oC over theCo/Al2O3 catalyst prepared byimpregnationmethod, butwhen considering hydrogen production and carbon resistance at the same time,Ni/Al2O3 ismost effective catalyst in gasoline steamreforming because it produced non-deactivatingcarbon. Ahigher thermal stabilityand graphitization degree of deposited carbonwere obtained onNi- Al2O3 and Co/Al2O3.

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