Hydrogen production via auto-thermal reforming of bio-ethanol: The role of iron in layered double hydroxide-derived Ni 0.35Mg 2.65AlO 4.5±δ catalysts

Abstract

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 (ATR) of ethanol for hydrogen production. The Ni 0.35Mg 2.65AlO 4.5±δ catalyst showed poor stability and a low H 2 yield, near 2.51 mol H 2/mol EtOH. The tetra-component catalyst of Ni 0.35Mg 2.65Al 0.50Fe 0.50O 4.5±δ, 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 CH 4 reforming activity also improved and C 2H 4 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 ATR were improved, and the acidity was constrained as well.