Ni/Mg-Al mixed oxide catalyst for the steam reforming of ethanol

A series of 10 wt% Ni-loaded Mg-Al mixed oxide supported catalysts were evaluated for the production of hydrogen via the steam reforming of ethanol. Mg-Al mixed oxide supported nickel catalysts were found to give superior activity, H-2 and COx product selectivity, and improved catalyst stability compared to the pure oxide supported nickel catalysts. Performance was dependent upon the A and Mg content of the support. At 923 K, the mixed oxide supported catalysts exhibited the highest H-2 and COx yields and were stable, showing no signs of deactivation after 20 h of operation. The improved performance of these catalysts was related to the incorporation of the pure oxides, MgO and Al2O3, into a MgAl2O4 phase. The formation of MgAl2O4 reduced nickel incorporation into the supports leaving nickel in its active form. In addition, the formation of MgAl2O4, a slightly basic material, exhibited moderate acidic and basic site strength and density compared to the pure oxide supported catalysts. Moderation of the acid-base properties improved the activity, selectivity, and stability of the catalysts by reducing activity for by-product reactions. (C) 2009 Elsevier B.V. All rights reserved.