Nickel[sbnd]cobalt catalyst supported on TiO₂-coated SiO₂ spheres for CO₂ methanation in a fluidized bed

Carbon dioxide (CO₂)methanation, which is the reduction of carbon dioxide to methane by hydrogen generated from renewable energy, is a promising process for carbon recycling. Towards large-scale implementation, (i)fluidized beds, which have excellent heat transfer, are promising to perform the highly exothermic reaction; and (ii)catalysts suitable for long-term use in fluidized beds are needed. In this study, a novel Ni[sbnd]Co bimetal catalyst supported on TiO₂-coated SiO₂ spheres (NiCo/TiO₂@SiO₂)was rationally designed and evaluated for CO₂ methanation in fluidized bed reactor. The results demonstrate that NiCo/TiO₂@SiO₂ exhibited high CO₂ conversion with CH₄ selectivity of greater than 95%. Moreover, the superior performance was sustained for more than 100 h in the fluidized bed reactor, affirming the long-term stability of the catalyst. Comprehensive characterizations were conducted to understand the relationship between structure and performance. This study is expected to be valuable for the potential implementation of the CO₂ methanation process in fluidized beds.