Hydrogen production via auto-thermal reforming of bio-ethanol: The role of iron in layered double hydroxide-derived Ni0.35Mg2.65AlO4.5±δ catalysts

Ni-based layered double hydroxide (LDH)-derived catalysts with Ni-Mg-Al-Fe-O were prepared via co-precipitation, and were tested in auto-thermal reforming (AIR) of ethanol for hydrogen production. The Ni0.35Mg2.65AlO4.5 +/-delta catalyst showed poor stability and a low H-2 yield, near 2.51 mol H-2/mol EtOH. The tetra-component catalyst of Ni0.35Mg2.65Al0.50Fe0.50O4.5 +/-delta, in which the trivalent component consists of both aluminum and iron, showed a promising performance in ATR of ethanol: not only did the H-2 yield remain stable near 3.7 mol H-2/mol EtOH during the 30-h test, but the CH4 reforming activity also improved and C2H4 disappeared in product gases. These improvements can be attributed to the synergic effect by both iron and nickel on the structural and electronic properties: the BET surface area was increased, the reducibility of the Ni metal and its resistance to oxidation in AIR were improved, and the acidity was constrained as well. (C) 2010 Elsevier B.V. All rights reserved.