Catalytic Synthesis of CO by Combining CO_2 Capture and Hydrogenation over Three-Dimensional Ni/CaO Networks

摘要

Three-dimensional Ni/CaO networks were synthesized using a precipitation-combustion method and applied for the combined CO_2 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 H_2. It was found that, compared with pure CaO, the addition of Ni not only greatly lowered the reaction temperature of calcium carbonate species with H_2 to CH_4 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 CO_2 adsorption capacity of 9.7 mmol/g and a CO_2 conversion of 57.5% after 20 cycles for the combined CO_2 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.