Catalytic reduction of carbon dioxide on Ni---Cu alloys

Catalytic reduction of CO2 with H2 was studied on Ni/SiO2, Ni1−χCuχ/SiO2 (χ = 0.05−0.9) and Cu/SiO2 in a closed circulating reaction system in order to obtain a highly active and selective catalyst for CO formation. The yield of CO from CO2 + H2 on Cu/SiO2 was about 60% and its selectivity was 97% or more. In a Cu-rich region, Ni---Cu catalysts exhibited high selectivity for CO formation, while CH4 was produced predominantly in a Ni-rich region. The activity of Ni0.1Cu0.9/SiO2 for the selective reduction of CO2 to CO was enhanced by twice that of Cu alone by the addition of small amounts of Ni.