Effect of Metal Additives on the Hydrogenation of Carbon Dioxide over Nickel Catalyst Prepared by Sol-gel Method

Catalytic hydrogenation of carbon dioxide was carried out over Ni-Si-Ox catalysts prepared by the sol-gel method. The M/Ni-Si-Ox (M=Na, K, Rb, Cs, Mg, Ca, Sr, Ba, and La) catalysts were prepared by the wet impregnation method and their catalytic activities were tested. Methane was exclusively produced over the Ni-Si-Ox and M/Ni-Si-Ox catalysts under the reaction conditions of 5 MPa at 473 K. The change of the catalytic activity is investigated with respect to the electronegativity of the M. The electronic interaction between nickel and the M is discussed on the basis of XPS results.