Nickel-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-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. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.