Ethanol steam reforming over Ni/ZnAl2O4-CeO2. Influence of calcination atmosphere and nature of catalytic precursor

The hydrogen production from ethanol steam reforming has been studied over Ni/ZnAl2O4-CeO2 catalysts. The influence of calcination atmosphere and nature of catalytic precursor was analyzed. The impregnation of Ni was carried out from two different nickel salts: nitrate (Nt) and acetate (Ac). The catalysts were obtained from the precursor calcination under reductive and oxidative atmospheres. The catalysts obtained from nitrate salt impregnation were the most carbon resistance measured as mmolC/mol reacted C2H5OH, and those obtained under a reductive atmosphere were the most stable, as evidenced by smaller activity losses. The Ni(Nt)/ZnAl2O4-CeO2 obtained under reductive atmosphere was the most active (steady state ethanol conversion = 88%) and stable (activity loss = 14%) under mild reforming conditions (7.8% C2H5OH inlet concentration, H2O:C2H5OH molar ratio = 4.9, reaction temperature = 650 °C and W/F=49 g min molC2H5OH−1W/F=49 g min molC2H5OH−1). The hydrogen selectivity was 49% and the main C-containing products were CO2, CO and C2H4O.

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► The catalysts prepared from a nitrate solution produce lower amounts of carbon.
► The catalysts obtained under reductive atmosphere were the most stable with smaller activity losses.
► An ethanol conversion of 88% with an activity loss of 14% was obtained over the best catalyst.