Hydrogenation of CO2 on Co–Ni Catalysts Produced by Low-Temperature Combustion Using Modified Silica Fabric

Co–Ni supported catalysts were prepared by low-temperature combustion of dried mixture of solutions of cobalt and nickel nitrates and urea after impregnation of silica fabric (>97% SiO₂) premodified with 5, 10, and 15 wt % Al₂O₃. Modification of support was carried out by low-temperature combustion of dried mixture of solutions of aluminum nitrate and urea. Prepared supports and related catalysts were characterized by XRD, SEM, EDS, and BET method. The unreduced catalysts were found to contain oxides and complex oxides of nickel and cobalt. Reduction of catalysts with hydrogen at 400°C for 1 h was shown to contribute to forming metallic phases of Co and Ni; however, the nickel phase was detected only in reduced catalyst on unmodified fabric. The catalytic activity of catalysts was determined in the temperature range of 150–400°С. It was found that the reduced catalyst on support modified with 5 wt % Al₂O₃ possesses the highest CO₂ conversion (61.8%) and methane yield (3.61 vol %) at 400°С.