Abstract: A series of Cu/Zn based catalysts with and without Ni, prepared by the co-precipitation method, has been studied for methanol decomposition.CO and H₂ are the major products.The Cu/Zn catalysts show a low initial activity and a poor stability.The formation of the CuZn alloys was observed in the deactivated Cu/Zn catalysts which were used for methanol decomposition at 250 ℃.When small amounts of Ni were added in the catalyst, the Cu/Zn/Ni(molar ratio 5/4/x) catalysts showed a high activity at a low temperature.The activity and the stability of the catalyst depend on the nickel content.The activity of the Cu/Zn/Ni catalysts was maintained at a relatively stable value of 78% conversion of methanol with 95% selectivity of H₂, 93%selectivity of CO, and a more than 70% yield of hydrogen was obtained at 250 ℃ when x≥1.The stability of the Cu/Zn/Ni(molar ratio 5/4/x) catalysts showed the maximum(ca 88%)when x＝1.The stabilization effect of nickel on the Cu/Zn based catalysts may lead to the increasing of the dispersion of active Cu species and the prevention of CuZn alloys formation.

Key words: Nickel, Cu/Zn catalysts, Stabilization, Methanol, Decomposition