Cobalt Supported Nickel Silicate Nanotubes for Efficient CO₂ Methanation

The unprecedented growth in economy and industry caused the rapid increase of CO₂ emission which impacts health and environment. The climate change and global warming are remarkable challenges calling for urgent need to mitigate CO₂ concentration in the atmosphere. The conversion of CO₂ into carbon-based fuel (methane) is the promising approach to pursue the goal of mitigation. The extensive studies of nickel-based catalysts in CO₂ methanation are due to the obvious superiorities such as the tremendous activity, availability, and low price. The nickel silicate (NiSil) nanotubes catalysts synthesized by solvothermal method and different loadings of Co species (0.25–1.0 wt%) were deposited by chemical deposition under sonication treatment. Various techniques such as XRD, TEM, FT-IR, DRUV-vis, XPS and N₂ physisorption were used to investigate the physicochemical properties of the catalysts. The results from the measurements confirmed the successful preparation of the Co deposited NiSil catalysts with the required physicochemical properties. Among the synthesized catalysts, 0.5Co–NiSil catalyst offered the highest CO₂ methanation activity, mainly due to the high surface area, pore volume, easy reducibility, and lower particle size. In addition, time on stream analysis revealed that the Co deposited NiSil catalysts exhibited considerable stability (48 h) without losing catalytic activity.