Physical mixing of TiO2 with sponge nickel creates new active sites for selective CO methanation†
Ni–α-Al2O3, Ni–SiO2, Ni–γ-Al2O3, Ni–TiO2, and Ni–ZrO2 were prepared by physical mixing of metal oxides with sponge Ni, and the effect of physical contact of the metal oxides with sponge Ni on selective CO methanation was examined. The prepared Ni–TiO2 catalyst removed CO more deeply and suppressed CO2 methanation better relative to the other catalysts. The metal oxide nature of the prepared Ni catalysts affected the CO2 methanation activity, as well as the reverse water gas shift activity. Moreover, the catalytic performance for the five catalysts was not related to contact time. These results predicted the appearance of new active sites between sponge Ni and the metal oxides.