Nickel based mixed oxide catalysts derived from Ni-Mg-Zn-Al hydrotalcite-like precursors are prepared and evaluated for H-2-rich gas production via ethanol steam reforming. It has been found that the catalyst properties (e.g. BET surface area, Ni dispersion and reducibility) and catalytic performance depend on the Mg:Zn molar ratio. MgO and ZnO have a synergetic effect. At 700 degrees C, the quaternary catalyst with a Mg:Zn ratio of 4 exhibits the highest H-2 yield and best stability, viz. no apparent variation of the product distribution over 100 h operation, whereas the ternary catalyst without Mg suffers severe coke accumulation after 7 h on-stream. Two types of carbon (filamentous and amorphous) are found deposited on the catalyst surface. The carbon deposited is dominated by filamentous carbon, which is likely originated from the decomposition of methane, and does not cause immediate deactivation. (C) 2011 Elsevier B.V. All rights reserved.