Catalytic Synthesis of CO by Combining CO2 Capture and Hydrogenation over Three-Dimensional Ni/CaO Networks

Abstract

Three-dimensional Ni/CaO networks were synthesized using a precipitation–combustion method and applied for the combined CO2 capture and catalytic hydrogenation as dual functional materials. NiO species were highly dispersed in the CaO substrate and generated small metallic Ni nanoparticles upon reduction with H2. It was found that, compared with pure CaO, the addition of Ni not only greatly lowered the reaction temperature of calcium carbonate species with H2 to CH4 and/or CO but also enhanced the conversion rate of calcium carbonate species, resulting in the clear increase in the productivity of CO. Ni/CaO exhibited excellent cyclic stability with a CO2 adsorption capacity of 9.7 mmol/g and a CO2 conversion of 57.5% after 20 cycles for the combined CO2 capture and hydrogenation, which was due to the elasticity of the three-dimensional network structure consisting of meso- and macropores to inhibit the growth and sintering of CaO particles.