Manganese-promoted nickel/alumina catalysts for hydrogen production via auto-thermal reforming of ethanol

The manganese-promoted nickel-based catalysts were prepared via wet-incipient impregnation, and tested in auto-thermal reforming (ATR) of ethanol for hydrogen production. The Ni/Al2O3 catalyst, in which Ni existed as NiAl2O4, produced a low H2 yield near 1.85 mol H2/mol ethanol. The Ni–Mn/Al2O3 catalyst showed a better performance in a 30-h test: the conversion of ethanol reached 100%, and a higher H2 yield remained stable near 3.1–3.2 mol H2/mol ethanol. This improvement can be attributed to the promotion of Mn: With Mn, the ilmenite-type NiMnO3 was formed, the reducibility of Ni–Mn/Al2O3 was thus improved, and there were more Ni0 over the surface of catalysts. Moreover, these Ni0 species were stable in the ATR test, as indicated by XRD and XPS.